Growth of ZnO nanorod arrays on soft substrates by hydrothermal process

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7）GROWTH OF ORIENTED SINGLECRYSTALLINE RUTILE TIO2 NANORODS ON TRANSPARENT CONDUCTING SUBSTRATES FOR
DYE-SENSITIZED SOLAR CELLS（2009）
水热法在FTO基板上合成定向单晶金红石TiO2纳米棒，丁氧钛在高压釜中，通过改变生长时间、反应浓度可以控制TiO2纳米棒的直径长度及密度。
NANORODS ON DYE-SENSITIZED SOLAR CELL EFFICIENCY（2010）
在FTO基板上先生长ZnO种层（Ar坏境中溅射ZnO 粉末），再生长ZnO纳米棒（低温水热法，硝酸锌六水合物溶于去离子水，用氨水调节PH值至10.3，生长温度60度）
种层退火：提高ZnO种层与FTO基板的附着力，使 ZnO纳米棒有效的生长
5) ZNO NANOTUBE BASED DYESENSITIZED SOLAR CELLS（2007）
60微米厚的模板有25%-50%的200纳米的孔，利用原子层沉积，形成AZO（掺铝氧化锌）
6）NANO-STRUCTURED CU2O SOLAR CELLS FABRICATED ON SPARSE ZNO
11) SOLUTION-PROCESSED CORE–SHELL NANOWIRES FOR EFFICIENT
PHOTOVOLTAIC CELLS（2011）
CdS–Cu2S同轴纳米线异质结太阳能电池，效率达到了5.4%
12) PHOTOVOLTAIC BEHAVIOR OF NANOCRYSTALLINE SNS/TIO2（2010）
通过化学液相沉积法将SnS 膜沉积在玻璃基板上，研究其性质。将SnS薄膜沉积在TiO2上研究其光伏特性。

超敏感的ZnO镀覆传感器在室温下对甲醛的影响

超敏感的ZnO镀覆传感器在室温下对甲醛的影响何一聪;罗浩;朱振【摘要】在本工作中,用介孔结构的甲醛传感器在室温下检测了甲醛(十亿分之几)浓度.通过 X-射线衍射(XRD)、Brunauer Emmett Teller(BET)和扫描电子显微镜(SEM)检测介孔氧化锌的形态和结构.测试了甲醛、甲醇、乙醇、丙酮和丙酮的传感特性.气体传感研究表明,介孔氧化锌在室温下对浓度为0.037 mg/m3的甲醛具有极好的敏感性.因此,介孔氧化锌在甲醛传感器领域有着广阔的应用前景.%In the present work, the formaldehyde sensor with mesoporous structure has been used to detect formaldehyde(parts-per-billion(ppb) concentrations) at room temperature. The morphology and structure of mesoporous ZnO were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET) and scanning electron microscopy (SEM). The sensing characteristics of formaldehyde, methanol, ethanol, hydrogen and acetone were examined. Gas sensing study revealed that mesoporous ZnO exhibited excellent sensitivity to formaldehyde at concentration as low as 0.037 mg/m3at room temperature. Therefore,mesoporous ZnO was a promising application in the field of formaldehyde sensor.【期刊名称】《广州化工》【年(卷),期】2018(046)005【总页数】3页(P61-63)【关键词】介孔氧化锌;甲醛;室温;气体传感器【作者】何一聪;罗浩;朱振【作者单位】天津理工大学环境科学与安全工程学院,天津 300384;天津理工大学环境科学与安全工程学院,天津 300384;天津理工大学环境科学与安全工程学院,天津 300384【正文语种】中文【中图分类】X851甲醛会造成鼻腔肿瘤、眼睛刺激、恶心、头痛、疲劳、迟钝、口渴、中枢神经损伤，免疫系统紊乱等症状[1]。

水热碳化法制备碳纳米材料

《纳米材料与纳米技术》论文水热碳化法制备碳纳米材料摘要：水热碳化法是一种重要的碳纳米材料的制备方法，本文综述了近年来以糖类和淀粉等有机物为原料，采用水热碳化法制备各种形貌可控碳纳米材料的研究现状，并提出了该方法研究中存在的问题以及今后可能的发展方向。

关键词：水热碳化法、碳纳米材料、碳微球、碳空心球、核壳结构复合材料1 引言形态可控的碳纳米材料由于独特的结构和性能而受到研究者的普遍关注[1]，常见的制备方法有化学气相沉积法(CVD)[2]、乳液法[3]和水热碳化法[4]等。

水热碳化法是指在水热反应釜中，以有机糖类或者碳水化合物为原料，水为反应介质，在一定温度及压力下，经过一系列复杂反应生成碳材料的过程[5]。

图1为水热碳化法所制备的各种形貌的碳材料。

与其他制备方法相比，采用水热碳化法所制备的纳米碳材料具有显微结构可调、优良的使用性能、产物粒径小而均匀等特点。

本文综述了水热碳化法制备形态可控碳纳米材料的最新研究进展，概括了工艺因素对碳纳米材料合成过程的影响，最后提出了水热法合成碳纳米材料今后可能的研究方向。

图 1 水热碳化法制备各种形貌碳材料的示意图2 水热碳化法制备碳微球碳微球由于具有大的比表面积、高的堆积密度以及良好的稳定性等，被应用于锂离子电池[6]、催化剂载体[7]、化学模板[8]、高强度碳材料[9]等方面，拥有广阔的应用前景。

Yuan等[10]以蔗糖为碳源，先采用水热碳化法合成碳微球，再使用熔融的氢氧化钾溶液对合成产物进行活化处理，制得粒径为100-150nm的碳微球。

研究表明活化后碳微球的石墨化程度有很大提高，且表现出良好的电化学性能。

其比容量达到382F/g，单位面积电容达到19.2μF/cm2，单位体积容量达到383F/cm。

Liu等[11]以琼脂糖为原料，采用水热碳化制备出粒径范围为100～1400nm的碳微球，研究结果表明碳微球的粒径随琼脂糖的浓度的增加而增大，且所制备的碳微球的表面富含大量的含氧官能团，这些官能团可以很好地吸附金属离子或者其它有机物等，因此该材料在生物化学、药物传输以及催化剂载体等方面具有很好的应用前景。

种子辅助化学法合成ZnO纳米棒及其表征

种子辅助化学法合成ZnO纳米棒及其表征钭启升(浙江海洋学院,杭州311258)摘要:低温条件下(95 ),采用ZnO种子辅助化学反应法,成功制备了宏量直、细的ZnO 纳米棒;用X射线衍射(XRD)、扫描电子显微镜(SE M)、透射电子显微镜(TEM)等分析手段对纳米棒的结构和形貌进行了表征;同时还对ZnO纳米棒的形成机理作了分析;并以ZnO纳米棒作为光催化剂,对甲基橙(MO)溶液进行了光催化实验。

结果表明,ZnO与Zn源的摩尔比对ZnO纳米棒的形貌影响很大,PVA通过空间位阻效应控制ZnO纳米棒的长度,ZnO纳米棒有较好的光催化活性。

关键词:ZnO纳米棒;种子辅助;化学反应法;生长机理;催化活性中图分类号:O782 1;TN304 21 文献标识码:A 文章编号:1003-353X(2010)06-0580-04Preparation of ZnO Nanorods at Low Temperature by Seed-AssistedChemical Reaction MethodDou Qisheng(Zhejiang Ocean Unive rsity,Han gzhou311258,China)Abstract:Hectogram-scale synthesizing straight and thin ZnO nanorods were synthesized by seed-assisted che mical reaction process at low temperature(95 ).The ZnO nanorods were characterized by X-ray diffraction(XRD),scanning electron microsc ope(SEM),transmission electron microscope(TE M). Further more,mechanism was discussed.Experiments were carried out using methyl orange as the pollutant object to evaluate the photocatalytic activity of ZnO nanorods.The results sho w that the molar ratio of ZnO seed and zinc source controls the growth of ZnO nanorods,(PVA)acts as a spatial obstructor to control the length of ZnO nanorods,the photocatalytic activity of the ZnO nanorods are strong.Key words:ZnO nanorods;seed-assisted;c hemical reaction;gro wn mechanism;photocatalytic ac tivity EEAC C:2520D;2550N0 引言ZnO是一种新型的直接宽禁带 - 族化合物半导体材料,室温下它的禁带宽度为3 37e V。

ZnO纳米阵列增强大功率蓝光LED出光效率的研究

ZnO纳米阵列增强大功率蓝光LED出光效率的研究徐冰;赵俊亮;张检明;孙小卫;诸葛福伟;李效民【摘要】采用低成本的化学溶液法在大功率GaN基蓝光LED芯片上生长ZnO纳米阵列,以提高LED芯片的出光效率.通过改变生长溶液中氨水及锌离子浓度实现对纳米阵列结构形貌的可控性,进而得到不同形貌的ZnO纳米阵列.在此基础上,进一步研究纳米结构形貌对LED芯片出光性能的影响,探讨纳米结构增强LED芯片发光效率的机理.结果表明,较高密度、锥形形貌的ZnO纳米阵列更有利于增强LED芯片的出光效率.在优化的实验条件下,表面沉积ZnO纳米阵列的LED芯片比普通LED的出光效率高出60％以上,并且纳米阵列不影响LED器件的电学性能和发光稳定性.%ZnO nano-arrays were grown on high power GaN blue LED chip by low-cost chemical solution methods, which aimed to enhance the light extraction efficiency of LED chip. Various morphology was achieved by adjusting the concentration of ammonia and Zn2+ in the growth solution. With different growth solution, ZnO nano-arrays exhibited different morphologies and densities. The effect of nano-array morphology on the light extraction performance of the ZnO nano-array coated LED chip were studied. The mechanism of light extraction efficiency enhancement by nano-arrays was also discussed based on the experimental results. The result shows that ZnO nano-arrays with higher density and cone-shaped morphology are favorable for the improvement of light extraction in LED chip. ZnO nano-arrays grown at the optimum conditions can enhance the light extraction of LED chip by more than 60%. Meanwhile, ZnO nano-arrays have no significant effect on the electrical properties and electroluminescence stability of LED chip.【期刊名称】《无机材料学报》【年(卷),期】2012(027)007【总页数】5页(P716-720)【关键词】ZnO纳米阵列;大功率LED芯片;出光效率;化学溶液法【作者】徐冰;赵俊亮;张检明;孙小卫;诸葛福伟;李效民【作者单位】天津大学理学院,应用物理系,天津市低维功能材料物理与制备技术重点实验室,天津300072;天津大学理学院,应用物理系,天津市低维功能材料物理与制备技术重点实验室,天津300072;天津大学理学院,应用物理系,天津市低维功能材料物理与制备技术重点实验室,天津300072;天津大学理学院,应用物理系,天津市低维功能材料物理与制备技术重点实验室,天津300072;中国科学院上海硅酸盐研究所,高性能陶瓷和超微结构国家重点实验室,上海200050;中国科学院上海硅酸盐研究所,高性能陶瓷和超微结构国家重点实验室,上海200050【正文语种】中文【中图分类】O472半导体照明(LED)光源是近些年快速发展的一种新型固态光源, 具有微型化、高效率、长寿命[1]、无汞、色彩丰富等显著优点, 成为世界公认的“第四代绿色照明光源”, 并且LED光源的效率理论上高达50%以上[2], 有望大幅度降低照明能耗. 目前, 固态白光照明LED面临的关键问题是提高效率和降低成本. 改善白光LED效率的有效途径之一是提高InGaN基蓝光LED芯片的发光效率(外量子效率). LED的外量子效率由内量子效率和光子提取效率(出光效率)共同决定, 现在LED内量子效率可达到 80%以上[3-4]. 内量子效率的提升空间很小, 出光效率成为制约LED 发光效率的瓶颈. 目前,大多数研究采用在 LED器件出光面通过纳米加工技术形成微凸透镜或光子晶体阵列[5-6]来增强 LED芯片的出光效率. 然而, 此方法通常需要昂贵的纳米精密加工设备, 增加了LED的成本. 最近研究发现在InGaN基LED的出光面上生长ZnO纳米阵列,可以使LED的出光效率提高50%以上[7-9]. ZnO纳米阵列可以通过自组装生长而无需复杂的纳米加工工艺[10], 并且ZnO作为新型宽禁带半导体材料具有高透光率、原料成本和加工成本较低等优势, 有望成为制作高效率低成本LED光源的可靠方法. 本工作主要通过水溶液法在GaN基蓝光LED芯片上生长ZnO纳米阵列, 并通过改变生长溶液中氨水和Zn2+的浓度控制纳米阵列的形貌、尺寸及排列密度来改善芯片的出光效率.1.1 实验原料采用的化学试剂均为分析纯级, 实验原料为六亚甲基四胺(C6H2N4), 乙二醇甲醚(C3H8O2), 单乙醇胺(C2H7NO), 二乙醇胺(C4H11NO2), PEI, 丙酮(C3H6O), 乙醇(C2H5OH), 硝酸锌(Zn(NO3)2·6H2O),盐酸(HCl), 氨水(NH3·H2O).1.2 实验过程用乙二醇甲醚做溶剂配置醋酸锌与单乙醇胺的溶胶溶液, 密封后放入烘箱中加热至60℃. 先将LED芯片放置在250℃的电热板上预热, 再放入上述溶胶溶液中通过浸渍—提拉法生长一层 ZnO籽晶层. 将生长好籽晶层的 LED芯片放入由Zn(NO3)2·6H2O、HMT(六亚甲基四胺溶液体系)、氨水和 PEI组成的生长溶液中密封, 并放入烘箱中90℃加热 2 h, 生长 ZnO 纳米阵列. 生长溶液中HMT和 PEI 的浓度分别固定在 0.125 mol/L与0.0059 mol/L, 而Zn2+(Zn(NO3)2·6H2O)浓度在 0.25~0.8 mol/L范围内变化, 氨水浓度在0.33~0.48 mol/L范围内变化. 1.3 性能表征通过场发射扫描电子显微镜(FESEM, JEOL公司, JSM–6700F)观察纳米ZnO阵列的微观形貌和结构, 分析纳米阵列的直立性、尺寸与密度.LED芯片的电学性能通过 I-V特性测试表征,测试在Keithley 2400数字源表与Keithley 2015万用表上完成, 样品放置在探针台(无锡市赛更特电子设备厂生产)上, 两个探针分别接触芯片的正负极,通过探针施加电压测试. 对表面生长有ZnO纳米阵列的LED芯片, 测试之前需要用微探针将覆盖在电极上的纳米阵列刮除, 以保证探针与电极的接触.LED芯片的光谱测试通过GSI80型紫外–可见–近红外波段光纤光谱仪(天津津科浩强公司生产)进行, 样品同样放置在探针台上, 通过探针施加电压发光后, 通过光纤传输至光谱仪收集.2.1 ZnO纳米阵列的微观结构图1为生长溶液中氨水浓度对纳米ZnO阵列形貌的影响. 可以发现, 随着氨水浓度增大, 纳米阵列长度明显变短. 这是由于氨水浓度较高时, 溶液中较高浓度的OH–离子降低Zn(NO3)2·6H2O的水解反应速率, 从而降低纳米ZnO阵列的生长速率.图2为不同Zn2+离子浓度溶液生长出的ZnO纳米阵列的 SEM 照片. 可能看出, Zn2+浓度从0.25 mol/L增加到0.4 mol/L时, 密度明显增大, 直径与长度也增加, 并且出现明显的锥形结构. 当Zn2+离子浓度继续增加时, 密度变化不再明显, 长度增加也不明显.图 3为在优化条件下生长的 ZnO纳米阵列的XRD 图谱, 除 ZnO(002)衍射峰外未发现其他衍射峰, 这表明纳米阵列为典型的纤锌矿ZnO晶体结构,并沿(002)面择优取向, 即沿 c轴垂直于衬底生长,与SEM观察到的结果一致.2.2 LED芯片的电学性能不同生长条件下LED芯片上生长ZnO纳米阵列之后的I-V曲线如图4和图5所示(图中均以未生长ZnO纳米阵列的LED芯片做参考, 在图中表示为reference).从图4与图5可以看出在不同浓度的氨水及不同浓度Zn2+下生长ZnO纳米阵列, LED芯片的电学性能没有显着变化, 都维持着很好的整流特性, 开启电压也基本维持在 2.6 V左右, 而正向电流与未生长纳米阵列的器件相比略有增加, 其原因为: 在生长ZnO纳米阵列之前生长了一层致密籽晶层, 该籽晶层可以沿衬底表面形成导电通道, 从而在一定程度上降低了器件的电阻, 但是由于ZnO薄膜电阻较大, 对于电流的增加贡献较小, 所以正向电流的增加不太明显. 由此可见, ZnO纳米阵列并不会对LED芯片的电学性能产生显着影响.2.3 LED芯片的光学性能文献[11-13]研究中发现, ZnO纳米阵列可以显著增强LED芯片的出光效率[11-13], 这是由于纳米阵列可以显著改善光子在LED芯片与空气界面处的全反射. ZnO 折射率介于 GaN与空气之间,在芯片表面生长纳米阵列后, 部分满足全反射条件的光线可以传输至纳米 ZnO中, 经过多次反射最终从顶端出射, 由此增强了LED芯片的出光效率.LED芯片在不同氨水浓度溶液中生长的 ZnO纳米阵列的发光光谱如图 6. 可以看出, 生长完纳米阵列后LED芯片的发光强度有所增加, 氨水浓度从0.33 mol/L增加到0.405 mol/L时, 芯片发光强度略有下降. 浓度进一步增加至 0.48 mol/L时, 芯片发光强度又提高至0.33 mol/L对应的水平. 由图6可以看出, 氨水浓度的变化对于发光强度的影响不显著.LED芯片在不同Zn2+浓度溶液中生长纳米阵列的发光光谱如图 7. 与氨水浓度相比, Zn2+浓度对LED芯片的发光强度影响更大. Zn2+浓度为0.4 mol/L时样品发光强度最强, 与参照LED芯片相比, 出光效率提高60%以上, 说明该条件下生长的纳米阵列具有最有效的光子提取作用. 而当 Zn2+浓度达到0.8 mol/L时发光强度又远低于参照LED芯片.由图 2可知, Zn2+浓度由 0.25 mol/L增加至0.4 mol/L时, 发光强度增强是由密度增加引起的,这与前期文献研究中有人提出高密度的纳米阵列可以更有效地增强LED出光效率一致[6]. 而 Zn2+浓度为0.4 mol/L的样品呈现出明显的锥形结构[8], 更利于提高LED芯片的出光效率. 而Zn2+浓度从0.4 mol/L增加至0.8 mol/L时, 纳米阵列结构并没有明显的变化, 但是出光效率明显下降, 这可能是由于溶液中过多的Zn2+增加了ZnO晶体中Zn间隙缺陷的浓度,缺陷对LED所发出的蓝光产生吸收, 从而降低了芯片的出光效率.为了进一步研究LED芯片的电致发光性能, 研究了表面长有纳米阵列的LED芯片与参照LED芯片的发光强度随电流关系曲线如图 8. 可以看出,各电流下纳米阵列LED芯片的发光强度都高于未生成纳米阵列的LED芯片, 并且LED芯片的发光强度随电流增加基本保持线性增加, 说明纳米阵列在增强LED芯片出光效率的同时, 不会对器件稳定性造成明显影响.采用低成本化学溶液方法在 GaN基大功率蓝光LED芯片上制备出ZnO纳米阵列, 阵列沿c轴垂直衬底生长, 具有较好的直立性. 纳米阵列生长溶液中氨水浓度与Zn2+浓度对纳米阵列形貌产生影响,进而影响 LED芯片的出光效率. 实验结果表明,Zn2+浓度对纳米阵列LED芯片出光性能的影响大于氨水的影响, 当Zn2+浓度为0.4 mol/L, 氨水浓度为0.48 mol/L 时, 纳米阵列具有锥形尖端形貌, 阵列密度较高, 此时LED芯片的出光性能最好. 与没有生长纳米阵列的LED芯片相比, ZnO纳米阵列可以增强LED出光效率60%以上, 并且不会对器件电学性能与发光稳定性造成影响.【相关文献】[1] 胡耀祖, 李丽玲, 李宏俊, 等. 照明节能技术发展趋势. 照明工程学报. 2008, 19(2): 1−6.[2] Phillips J M, Coltrin M E, Crawford M H, et al. Research challenges to ultra-efficient inorganic solid-state lighting. Laser &Photon Rev., 2007, 1(4): 307−333.[3] Nishida T, Saito H, Kobayashi N, et al. Milliwatt operation of Al-GaN-based single-quantum-well light emitting diode in the ultraviolet region. Appl. Phys. Lett., 2001, 78(25): 3927−3928.[4] Fujii T, Gao Y, Sharma R, et al. Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening.Appl. Phys. Lett., 2004, 84(6): 855−857.[5] McGroddy K, David A, Matioli E, et al. Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes. Appl. Phys. Lett., 2008, 93(10): 103502−1−3.[6] Kwon M K, Kim J Y, Park I K, et al. Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal. Appl. Phys. Lett., 2008, 92(25):251110−1−3.[7] Zhong J, Chen H, Saraf G, et al. Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency. Appl. Phys.Lett., 2007, 90(20): 203515−1−3.[8] Chiu C H, Lee C E, Chao C L, et al. Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs. Electrochemical and Solid-State Letters. 2008,11(4): 84−87.[9] An Sung Jin, Chae JeeHae, Yi Gyu-Chul, et al. Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays. Appl. Phys. Lett., 2008, 92(12):121108−1−3.[10] Qiu Jijun, Li Xiaomin, Zhuge Fuwei, et al. Solution-derived 40 μm vertically aligned ZnO nanowire arrays as photoelectrodes in dye-sensitized solar cells. Nanotechnology. 2010, 21(19): 1−9.[11] Kim Kyoung-Kook, Lee Sam-dong, Kim Hyunsoo, et al. Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution. Appl. Phys.Lett., 2009, 94(7): 071118−1−3.[12] Kuo C H, Chen C M, Kuo C W, et al. Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers. Appl. Phys. Lett., 2006, 89(20):201104−1−3.[13] Ye Jing, Zhao Yu, Tang Libin, et al. Ultraviolet electroluminescence from two-dimensional ZnO nanomesh/GaN heterojunction light emitting diodes. Appl. Phys. Lett., 2011, 98(26):263101−1−3.。

汉中市人民政府关于表彰第十一届自然科学优秀学术论文的通报

汉中市人民政府关于表彰第十一届自然科学优秀学术论文的通报文章属性•【制定机关】汉中市人民政府•【公布日期】2018.08.09•【字号】汉政函〔2018〕44号•【施行日期】2018.08.09•【效力等级】地方规范性文件•【时效性】现行有效•【主题分类】教育正文汉中市人民政府关于表彰第十一届自然科学优秀学术论文的通报各县区人民政府，汉中经济开发区管委会，市政府各工作部门、直属机构：近年来，全市上下认真实施“科教兴汉”、“人才强市”战略，全市广大科技工作者潜心钻研，大胆创新，取得了一批自然科学成果及优秀学术论文。

根据《汉中市自然科学优秀学术论文评选办法》，经汉中市第十一届自然科学优秀论文评选委员会评审，评选出本届自然科学类优秀学术论文102篇。

其中：《HCV感染者中血清外泌体miRNA-122的检测及其临床意义》等10篇论文评为一等奖；《不同分子分型的乳腺癌前哨淋巴结转移与临床病理特征的关系研究》等41篇论文评为二等奖；《不同性诱剂对亚洲玉米螟的引诱效果比较及田间应用初探》等51篇论文评为三等奖。

为了鼓励全市科技工作者不断加强学术创新，为促进汉中“三市”建设和经济社会持续科学发展做贡献，市政府决定对全市第十一届自然科学优秀学术论文及作者予以表彰。

希望受到表彰的同志再接再厉，不断探索奋进，在各自工作领域作出新的更大成绩。

全市科技工作者要向受表彰的同志学习，紧紧围绕我市科技、经济、社会科学发展的重大课题，深入研究，克难攻关，锐意进取，多出成果，全面推进我市科技进步和经济社会又好又快发展。

附件：汉中市第十一届自然科学优秀学术论文获奖名单汉中市人民政府2018年8月9日附件：汉中市第十一届自然科学优秀学术论文获奖名单一等奖论文（10篇）论文名称HCV感染者中血清外泌体miRNA-122的检测及其临床意义carcinoma identified by cross talk genes in disease related pathways 通过疾病相关通路的串扰头皮轴型血管网皮瓣或带阔筋膜的股前外侧穿支皮瓣修复头皮恶性肿瘤患者根治性切除术缺损的效果籼稻骨干亲本稻瘟病抗性基因pi-b的检测基于STR分型检测技术的89份茶树种质资源遗传多样性分析秦巴山区黄牛群体的微卫星DNA遗传多样性陕南老茶树扦插茶苗资源遗传多样性分析原位水热法在介孔TiO2光阳极中生长ZnO纳米线增强量子点敏化太阳能电池的光捕获dots and their application in constructing a fluorescent turn-on nanoprobe for imaging of 荧光碳点的制备及在构建细胞内硒醇纳米探针中的应用）Interfacial properties of stanene–metal contacts（锡烯与金属接触的界面性质）二等奖论文（41篇）不同分子分型的乳腺癌前哨淋巴结转移与临床病理特征的关系研究might participate in protecting the pupating larva from microbial infection（家蚕茧丝中的蛋白染）汉中市中心城区常绿行道树综合评价is associated with the risk of intrahepatic cholangiocarcinoma MicroRNA-150在胆管细胞性肝癌秸秆还田对汉中盆地稻田土壤有机碳组分、碳储量及水稻产量的影响大棚温湿条件对草莓生长结实及土传病害的影响西瓜雄性不育系“se18”抗氧化酶活性和内源激素含量变化分析汉中面皮水磨米粉的加工技术优化研究三倍体毛白杨生长量数学模型建立及验证抗凝剂对动物布鲁氏杆菌病虎红平板凝集试验的影响421CC were significantly Associated with longer progression-free survival in Chinese breast 应用液相阻断EISA试验和正向间接血凝试验（IHA）检测猪（O）型口蹄疫抗体的比较分析机插秧不同插植密度对水稻纹枯病发生及危害影响的初步研究不同栽培规格对魔芋根状茎生长特性及产量的影响6个蓝莓品种在汉中地区的丰产性试验不同厂家猪O型口蹄疫灭活苗免疫效果研究城固县农作物病虫害绿色防控技术示范实践探索地佐辛治疗晚期癌症患者伴中度及中度疼痛的疗效及安全性观察籼粳交水稻花药培养条件的优化不同果桑品种资源的生长结实特性调查初报可见分光度法在布鲁氏杆菌病试管凝集试验结果判定中的应用不同基质对曼地亚红豆杉扦插成活率的影响MODS患者外周血单个核细胞内PPARγ与NF-κB的表达和关系两种不同途径胆道金属支架植入治疗恶性阻塞性黄疸的对比研究腔镜保留残胃的双通道重建术在食管胃结合部癌中的应用mphocyte ratio improves the predictive power of GRACE risk score for long-acute coronary syndrome 血小板与淋巴细胞比例改善GRACE风险评分对急性冠状动脉综合征患者长期心血管小儿颈深部感染33例分析早期24h内血浆BNP动态变化与重症急性胰腺炎近期死亡的相关性研究the Interface Optical Phonon Spectrum in Wurtzite GaN/AlxGa1?xN Quantum Wells 中文：纤锌矿xN 的界面光学声子谱及其混晶效应阴道镜Reid评分对HIV阳性妇女宫颈癌筛查的诊断价值新方法初治结核性胸膜炎的疗效观察对有乳头发育的乳头内陷采用钢丝十字交叉牵引矫正术的临床体会electrochemical performance of Al-doped ZnO thin films hydrothermally grown on graphene-te bilayer flexible substrates （PET?石墨烯双层柔性衬底上水热生长Al掺杂ZnO薄膜的光电和电化学性基于图像技术的空中加油辅助指引系统via scanning a one dimensional linear unfocused ultrasound array 基于非聚焦多元线性阵列探汉中市空气污染特征及其气象条件分析f Well-Aligned ZnO Nanorod Arrays by Chemical Bath Deposition for Schottky Diode Applicatio陕钢集团烧结配加兰炭的工业试验lic acids and fluorescence properties in the solid state （苯并[c]香豆素羧酸衍生物的合及固体human immunoglobulin G: Elucidation of the cytotoxicity of CNPs and perturbation of immunog颗粒与人免疫球蛋白之间的相互作用：碳纳米颗粒的毒性及其对人免疫球蛋白构象影响的研究）ness of TC4-Based Laminated Composites Reinforced with Ti Aluminide and Carbide （TiAl合金层复合板材的弯曲强度和断裂韧性）三等奖论文（51篇）不同性诱剂对亚洲玉米螟的引诱效果比较及田间应用初探甘蓝型半冬性三隐性细胞核雄性不育系SY12A的选育秦巴山区珠芽魔芋种芋繁育方法比较及示范植酸与植酸酶在家禽生产中的应用研究缓释肥对机插稻生长发育及产量的影响中山柏苗木大小与移植成活率的关系汉中超级稻品种筛选试验汉中市元胡种植气候区划奶牛结核病PPD皮内变态反应检测技术应用中的问题讨论汉中茶树病虫害绿色防控存在的问题及对策汉中市森林生态文化体系建设规划与思考汉中水稻机械插秧插值深度试验初报喷施不同浓度的氨基寡糖素对柑橘生产的影响齐口裂鳆鱼人工繁育技术研究小麦茎基腐病的初步研究黄连木矮化林分的建设与探讨汉中水稻机械化插秧适宜新品种筛选试验初报汉中盆地水稻土有机质状况分析研究新型大鲵仿生态繁殖池建造结构及使用方法不同育秧剂对陕南稻麦油两熟区机插秧秧苗素质与栽插质量的影响一例鸭舟形嗜气管吸虫病诊断与治疗热疗联合FOLFOX4方案治疗晚期原发性肝癌的临床观察陕南油菜机械化生产现状及关键技术汉江河滩林下段木香菇高效栽培技术探讨一起疑似鸡白痢的诊治体会不同质量的魔芋球茎及药剂处理对魔芋软腐病田间控病保苗效果研究血栓弹力图在隧道式带涤纶套导管血栓栓塞中的作用晚期鼻咽癌同步放化疗临床研究以肺外症状为首发表现的儿童肺炎支原体感染85例特征分析改良预埋球囊技术对分叉病变分支小血管保护的临床疗效观察免散瞳数码眼底照相在老年眼底病中的筛查价值成人噬血细胞综合征8例临床分析普通型骨水泥股骨头假体置换与内固定治疗老年股骨粗隆间粉碎性骨折的对比研究喜炎平注射液联合小儿豉翘清热颗粒治疗儿童急性上呼吸道感染的临床研究某三级综合医院住院患者医院感染情况调查外源H2O2对低温胁迫下柑橘叶片抗寒性的影响近10年汉台区酸雨变化特征及气象条件分析具有最小荧光响应伪影的低亲和锌传感器汉江上游纤毛虫群落结构及与环境理化因子的关系汉钢1号高炉延长寿命的途径探析依帕司他联合甲钴胺治疗糖尿病周围神经病变的疗效及复发率pBabe-GLS1 真核表达载体构建及其对结肠癌细胞增殖、谷氨酰胺摄取的影响中医综合外治法治疗婴幼儿伤食泻254例临床观察儿童面部擦伤后真菌感染1例with cyclopentanone and furfural derived from Hemicellulose （用来源于半纤维素的环戊酮与糠料前驱体)开口箭大小孢子发生及雌雄配子体发育研究oil and its effects on microbial communities metabolism and enzyme activities （汉江上游铁壤微生物群落代谢和酶活性的影响）GaN:Mn 纳米粒子的磁性量子隧穿效应SBA-15 with thick pore wall and high hydrothermal stability （厚孔壁高水热稳定性SBA-15的合单侧开窗减压椎间融合内固定治疗老年退行性腰椎管狭窄症辛伐他汀对尿毒症患者微炎症的影响。

ZnO纳米棒阵列的可控生长与表征

ZnO纳米棒阵列的可控生长与表征摘要：采用化学溶液法在沉积了ZnO种子层的SnO2:F导电玻璃衬底上，生长了ZnO纳米棒阵列。

研究了1，3-丙二胺浓度对纳米棒阵列的形貌结构的影响规律。

采用扫描电镜（SEM），X射线衍射（XRD）对ZnO纳米棒的表面形貌和晶格结构进行了表征。

SEM结果表明纳米棒阵列垂直衬底表面生长，XRD结果表明纳米棒生长方向沿着［002］晶向，具有单晶结构。

1，3-丙二胺浓度对制备得到的纳米棒形貌、长度等有明显调控作用。

在优化条件下生长的ZnO纳米棒的长度大约7m and the diameters about10nm at the tip and150nm at the base were obtained.The optical property of ZnO nanorod arrays was characterized by photoluminescence measurement at room temperature.Key words：ZnO；chemical solution route；nanorod arrayZnO是一种非常重要的直接带隙II-VI族氧合物半导体，具有优异的光电性质。

ZnO禁带宽度为3.37eV，其激子束缚能为60meV，可以实现室温下的激子发射，产生近紫外的短波发光。

ZnO的导电性质具有良好的可控性，通过掺杂，ZnO的电阻率可以在10・cm之间变化。

另外ZnO还具有很好的压电性质，场发射特性，导热特性和光催化性质等［1］。

纳米结构的ZnO由于其独特的物理特性及在光电子器件方面的巨大潜力，备受关注。

规则排列的ZnO纳米棒针列是目前研究最多的体系之一，它在太阳能电池［2］、光学减反射层［3］、纳米发电机［4］、纳米紫外激光器等领域有着非常重要的应用前景［5］。

ZnO纳米棒阵列常用的制备工艺包括化学溶液沉积［6］、化学气相沉积［7］、热蒸发［8］、电化学沉积［9］和磁控溅射等等［10］。

2013-Electrochemical Deposition of ZnO Hierarchical Nanostructures from Hydrogel Coated Electrodes

doi: 10.1149/2.064304jes2013, Volume 160, Issue 4, Pages D156-D162.J. Electrochem. Soc.Shuxi Dai, Yinyong Li, Zuliang Du and Kenneth R. CarterNanostructures from Hydrogel Coated ElectrodesElectrochemical Deposition of ZnO Hierarchical serviceEmail alertingclick here in the box at the top right corner of the article or Receive free email alerts when new articles cite this article - sign up /subscriptionsgo to: Journal of The Electrochemical Society To subscribe to © 2013 The Electrochemical SocietyD156Journal of The Electrochemical Society ,160(4)D156-D162(2013)0013-4651/2013/160(4)/D156/7/$31.00©The ElectrochemicalSocietyElectrochemical Deposition of ZnO Hierarchical Nanostructures from Hydrogel Coated ElectrodesShuxi Dai,a,b Yinyong Li,a Zuliang Du,b,z and Kenneth R.Carter a,za Departmentof Polymer Science and Engineering,University of Massachusetts Amherst,Conte Center for PolymerResearch,Amherst,Massachusetts 01003,USAb Key Laboratory for Special Functional Materials of Ministry of Education,Henan University,Kaifeng 475004,People’s Republic of ChinaThe electrochemical deposition of ZnO hierarchical nanostructures directly from PHEMA hydrogel coated electrodes has been successfully demonstrated.A variety of hierarchical ZnO nanostructures,including porous nanoﬂakes,nanosheets and nanopillar arrays were fabricated directly from the PHEMA hydrogel coated electrodes.Hybrid ZnO-hydrogel composite ﬁlms were formed with low zinc concentration and short electrodeposition time.A dual-layer structure consisting of a ZnO/polymer and pure ZnO layer was obtained with zinc concentration above 0.01M.SEM observations and XPS depth proﬁling were used to investigate ZnO nanostructure formation in the early electrodeposition process.A growth mechanism to understand the formation of ZnO/hydrogel hybrid hierarchical nanostructures was developed.The I-V characteristics of the ZnO-hydrogel composite ﬁlms in dark and under ultraviolet (UV)illumination demonstrate potential applications in UV photodetection.©2013The Electrochemical Society.[DOI:10.1149/2.064304jes ]All rights reserved.Manuscript submitted December 11,2012;revised manuscript received January 28,2013.Published February 15,2013.ZnO is one of the most attractive oxide semiconductor materi-als with a wide bandgap (3.4eV)and large exciton binding energy (60meV)for promising applications in optoelectronic devices.1The fabrication of a variety of ZnO nanostructures,such as one dimen-sional nanowires/nanorods and two dimensional nano-structures have been extensively studied in the last two decades.2,3Recently,hierarchi-cal nanostructures have attracted considerable attention owing to their promising applications to nanodevices such as light-emitting diodes,4ﬁeld-effect transistors,5chemical sensors,6solar cells,7etc.There have been many reports about the physical methods to fabricate hierarchi-cal ZnO nanostructures including high temperature chemical vapor deposition (CVD),8thermal evaporation 9and pulsed laser deposition (PLD).10,11However,the high growth temperature limits the choice of substrates and requires expensive vacuum equipment.12It still re-mains a challenge to develop simple and reliable low-temperature fabrication methods for ZnO hierarchical nanostructures with con-trolled morphology and crystal nature.Hierarchical ZnO nanostructures can be synthesized at low-temperatures by various method including chemical bath deposition,13hydrothermal synthesis,14and eletrodeposition.15Among these solu-tion based growth methods,electrochemical deposition (ECD)is a rapid and cost-effective approach for the fabrication of hierarchical ZnO nanostructures.16Peulon et al.17and Izaki et al.18,19have per-formed pioneering work in the ﬁeld of electrodeposition of ZnO thin ﬁlms and nanorods on ITO substrates.There have been a variety of reports on the electrochemical synthesis of ZnO nanostructures on various substrates,including GaN,20FTO,21Au/Si,22Zn foils.23However,there are only a few reports on the electrodeposition of ZnO nanostructures on electrodes modiﬁed with functional materi-als.Recently,Seong et al.prepared ZnO nanosheets and nanorods structures by electrodeposition on single-walled carbon nanotubes modiﬁed electrodes.24In particular,Ryan et al.had successfully elec-trodeposited ZnO nanostructures onto organic-semiconducting sub-strates comprising copper phthalocyanine and pentacene molecular thin ﬁlms using a two-step electrochemical process.25Hybrid organic–inorganic composite materials have attracted in-terest over the last decade.26A polymeric matrix not only provides a mechanical support for the functional inorganic materials but also add new interesting features to the hybrid materials.27Because of its water-swelling and biocompatible properties,poly(hydroxyethyl methacrylate)(PHEMA),a material widely used in hydrogels,has been commonly employed as polymer matrix materials for the fabrica-tion of inorganic materials to get functional hybrid materials for many potential applications in photonics and biosensors.28The importantzEmail:zld@ ;krcarter@advantage consists in combining useful properties of both constitut-ing components,e.g.the ﬂexibility and shaping versatility of PHEMA hydrogel and optoelectronic response of the inorganic component.29Many studies have been devoted to the preparation of PHEMA-based composite materials with organic HEMA monomers and in-organic precursors such as tetraethoxysilane (TEOS)or titanium-oxo through conventional sol-gel processes.30To our knowledge,the elec-trodeposition of ZnO on the three-dimensional networks of a hy-drogel and the study of the growth mechanism for the deposition of ZnO nanostructures on the hydrogel coated substrates have not yet been reported.It represents a new motif for the generation of inorganic/organic hybrid materials with useful electrical and optical properties.In this study,ZnO hierarchical nanostructures were synthesized by a simple electrodeposition method directly from the PHEMA hy-drogel coated electrodes (Scheme 1).This new method provides a simple and unique approach to fabricate hybrid polymer/ZnO compos-ite ﬁlms.Various hierarchical ZnO nanostructures were synthesized on the hydrogel coated electrodes.The growth mechanism is also discussed to understand the formation of ZnO/polymer hybrid hier-archical nanostructures.Hybrid UV photodetector devices based on Au/ZnO-hydrogel/ITO structures were fabricated.The expected UV photoresponse of the electrodeposited polymer/ZnO composite ﬁlms was observed.This study provides a simple and unique approach to fabricate low-cost hybrid UVdetectors.Scheme 1.Schematic diagram of the three-electrode setup for the electro-chemical deposition of ZnO hierarchical nanostructures on PHEMA hydrogel coated electrodes.Journal of The Electrochemical Society,160(4)D156-D162(2013)D157ExperimentalAll organic reagents and solvents were purchased from Sigma-Aldrich and used without further puriﬁcation unless otherwise stated.Electrolyte solutions were prepared by dissolving zinc nitrate hex-ahydrate(Zn(NO3)2•6H2O),Aldrich,99%)at concentrations rang-ing from0.0001to0.2M in deionized water.Indium tin oxide(ITO)coated glass substrates(thickness:145±10nm,resistivity:20±2 /sq)were purchased from Thin Film Devices Inc.All ITO sub-strates were cleaned through ultrasonic treatment in isopropanol and acetone for10minutes and then by O2ICP/RIE etch for300s to remove organic contaminants.Poly(2-hydroxymethyl methacrylate)(PHEMA)hydrogel pre-cursor was synthesized by reacting of19.7mM hydroxyethylmethacrylate,0.3mM trimethoxysilyl propyl methacrylate(providingcrosslinkable functional group)and0.15mM azobisisobutyronitrilein10.5g dimethylformamide at55◦C for3hours.The PHEMAﬁlmswith different thickness were prepared on ITO substrates by spin-coating20wt%dimethylformamide solution of PHEMA at speedsbetween1000and5000rpm for60s.The thickness of PHEMAﬁlmscan be easily controlled by adjusting the concentration of PHEMAsolution and spin speed.The PHEMAﬁlms were cured on at100◦Con a hot plate for6hours to obtain crosslinked hydrogelﬁlms.ZnO thinﬁlms with various nanostructures were fabricated bycathodic electrodeposition from zinc nitrate aqueous solutions.Theelectrodeposition and electrochemical measurements were performedwith a CHI600D electrochemical workstation.Scheme1showsthe schematic diagram for the fabrication of ZnO nanostructureson crosslinked PHEMA coated ITO by electrochemical deposition.A standard three-electrode conﬁguration was used.The crosslinkedPHEMA coated ITO was used as the working electrode(cathode),aPt wire as counter electrode,and an Ag/AgCl(KCl saturated)as thereference electrode.The electrochemical cell was placed in the waterbath and the deposition temperatureﬁxed at70◦C.All experimentswere carried out potentiostatically in the range of−1000to−1200mV.Immediately after electrodeposition,the ZnOﬁlms were removedfrom the cell and rinsed with deionized water and dried with N2ﬂow.Film thickness measurements of PHEMA and ZnOﬁlms wereperformed with a Veeco Dektak150proﬁlometer.A Trion TechnologyPhantom III inductively coupled plasma(ICP)reactive ion etcher(RIE)was used to clean the ITO substrates.X-ray diffraction(XRD)patterns of ZnO thinﬁlms were collected using Cu Kαradiation(λ=1.5406Å)on a PANalytical X’Pert PRO diffractometer operating at45kV and40mA.The surface morphology and structures of as-prepared ZnOﬁlms were observed by a JEOL JSM6320F scanning electron microscopy(SEM)operated at5kV.XPS measurements were performed on a Physical Electronics Quantum2000Microprobe XPS instrument using a50W monochromatic Al X-ray(1486.7eV) source at a takeoff angle of45◦with a200μm spot area.The depth proﬁles of samples were acquired with2keV Ar+ion sputtering.The XPS data were analyzed using the Multipak software.Hybrid UV photodetector devices based on Au/ZnO-hydrogel/ITOstructures were fabricated.Top Au electrodes were thermally evap-orated through shadow masks onto the electrodeposited ZnO layersunder vacuum.A365nm UV light was used as the light source for thephotoconductivity experiments.The I–V characteristics of the deviceswere measured with a Keithley4200semiconductor characterizationsystem at room temperature in ambient air.Results and DiscussionThe morphology of the ZnO hierarchical nanostructures fabri-cated on hydrogelﬁlms via electrochemical deposition was observedby SEM.Figure1shows the typical top view and cross-sectionalSEM images of typical ZnO nanostructures cathodically depositedwith constant electrochemical parameters(Zn2+=0.1M,T=70◦C, t=1000s,E=−1.1V)on PHEMA hydrogelﬁlms with different thickness.As shown in Figure1a,nanoﬂake structures were obtained on the500-nm-thick PHEMA hydrogelﬁlms after1000selectrode-Figure1.Top-view and cross-sectional SEM images of ZnO nanostructures electrodeposited at70◦C in0.1M zinc nitrate solution under−1.1V for 1000s on PHEMA hydrogelﬁlms with thickness of(a,b)500nm and(c,d) 250nm.Scale bar=1μm.position.The nanoﬂakes have a thickness of about50nm and length ranging from200nm to1000nm.Figure1c presents the crystalline ZnOﬁlm with ridge-like surface morphology deposited on the250-nm-thick PHEMA hydrogelﬁlms.Cross-section images of Figure1b and1d clearly show a dual layer structure of electrodeposited ZnO ﬁlms.The bottom layer corresponded to a PHEMA/ZnO composite ﬁlm and the top layer corresponded to a pure layer of crystalline ZnO hierarchical nanostructures.For the ZnO nanostructures deposited on the500-nm-thick PHEMA hydrogel(Figure1b),the top layer of crys-talline ZnOﬁlm was3μm thick.The1.5μm thickness of the bottom layer of PHEMA/ZnO compositeﬁlm is about3times larger than that of the original500-nm dry PHEMA hydrogel.Swelling measure-ments of crosslinked PHEMA hydrogels were performed under the same electrodeposition condition.The crosslinked PEMA hydrogel exhibited swelling behavior with an average swelling ratio of about 1.21measured after immersion in the zinc nitrate solution for30min at70◦C.This indicated the increased thickness of ZnO/PHEMA com-positeﬁlms compared to that of a dry PHEMA hydrogelﬁlm is largely inﬂuenced by the formation and growth of ZnO nanocrystals inside the PHEMA hydrogel three dimensional networks.Our experiments reveal that the morphology and crystal nature of the electrodeposited ZnO hierarchical structures on PHEMA hydrogel coated ITO could be tuned by adjusting the deposition conditions,such as concentration of zinc ions in the electrolyte,applied potential and electrodeposition time.Figure2presents the SEM images of ZnO nanostructures cathodically deposited on crosslinked PHEMA coated ITO with increasing zinc nitrate solutions from0.01M to0.2M with other constant electrochemical parameters(E=−1.1V,T=70◦C, t=1000s,hydrogelﬁlm thickness=500nm).Figure2a shows the surface morphology of ZnOﬁlms deposited on the PHEMA coated ITO in the0.01M zinc nitrate solution.A relativelyﬂatﬁlm composed of particles with a size ranging from100to300nm and some pieces of thin nanoﬂakes with a thickness of50nm can be observed.As the electrolyte concentration increased to0.05M,irregular porous surfaces appeared on the PHEMA/ITO electrode.Figure2b clearly shows the porous network structures of nanoﬂakes with thick-ness of50-100nm.The diameter of large pores in the porous network is about400–800nm.Nanoﬂakes with a thickness of50nm and length less than1μm were obtained after1000s electrodeposition in 0.1M electrolyte(Fig.2c).Figure2d presents typical morphology of sheet-like ZnO nanostructures obtained in0.2M zinc ions solution. The nanosheets had unordered orientations and smooth surfaces with thickness less than100nm and width of2–3μm.Figure3shows the XRD patterns of the electrodeposited ZnOﬁlms on the PHEMA hydrogel coated ITO substrates at70◦C under−1.1VD158Journal of The Electrochemical Society,160(4)D156-D162(2013)Figure2.Top view SEM images of ZnOﬁlms electrodeposited on PHEMA hydrogel coated ITO substrates with constant electrochemical parameters (E=−1.1V,T=70◦C,t=1000s,hydrogelﬁlm thickness=500nm) at different Zn(NO3)2concentrations of(a)0.01M,(b)0.05M,(c)0.1M and (d)0.2M.Scale bar=1μm.for1000s at different Zn ions concentrations range from0.001M to 0.1M.The Zn ion concentration was found to inﬂuence the growth rate and the crystal nature of theﬁlms.A higher concentration of Zn ions had resulted in a faster growth rate.There is no obvious diffraction peak of ZnO for theﬁlm electrodeposited in the0.001M for1000 s(Pattern b).Crystalline ZnO was formed only when the zinc ion concentration increased to0.01M.For XRD pattern c to e,the XRD diffraction peaks can be indexed as hexagonal wurtzite structured ZnO,which is in good agreement with the literature values(JCPDS card,No.36-1451)16except the peaks marked with an asterisk symbol that result from the ITO substrate(JCPDS,No.06-0416).The ZnO ﬁlm deposited in the zinc nitrate solution above0.05M exhibits good crystallinity and no signal corresponding to Zn metal or other oxides is found.The presence of(100),(002)and(101)peaks indicated the random orientation of the ZnOﬁlms,which correspond to the SEM observation in Figure2.The electrochemical reaction is also determined by the electrode-position potential.31Figure4shows the SEM images of ZnOnanos-Figure3.XRD patterns of(a)ITO substrate and ZnOﬁlms eletrodeposited on PHEMA hydrogel coated ITO at70◦C under−1.1V for1000s at different Zn(NO3)2concentrations of(b)0.001M,(c)0.01M(d)0.05M,(e)0.1M.Figure4.Top-view and cross-section SEM images of ZnOﬁlms electrode-posited at70◦C for1000s in0.05M Zn(NO3)2on500-nm-thick PHEMA hydrogel coated ITO substrates under different applied potentials of(a,b)−1.0V,(c,d)−1.1V and(e,f)−1.2V.Scale bar=1μm.tructures cathodically deposited on PHEMA coated ITO with constant electrochemical parameters(Zn2+=0.01M,T=70◦C,t=1000s, PHEMAﬁlm thickness=500nm)under different applied potentials of−1.0V,−1.1V and−1.2V(versus Ag/AgCl).Figure4a shows the low magniﬁcation and high magniﬁcation SEM images(insert image in Fig.4a)of the electrodeposited ZnOﬁlms under−1.0V withﬂat and compact surfaces.The morphology of ZnOﬁlms deposited under −1.1V shows a porous nanoﬂake structures(Fig.4c).The ZnOﬁlm electrodeposited under potentiostatic condition of−1.2V displays morphology of submicron pillar arrays.The diameters of the hexag-onal faced pillars are in the range of500-800nm.The submicron pillar arrays show a relative preferential c-axis perpendicular to the substrate.These observations are in accordance with the presence of a strong(002)peak in XRD data.According to the top-view SEM images(Fig.4a,4c and4e),the surface of electrodeposited ZnOﬁlms becomes more rough with the increased negative applied potential.The morphology changes from aﬂat surface to porous nanoﬂakes structures and then to submicron pillar arrays.Cross-section images of Figure4b,4d and4f clearly show the dual layer structures of electrodeposited ZnOﬁlms.The PHEMA/ZnO composite layers deposited under different applied po-tentials of−1.0V,−1.1V and−1.2V had a thickness of1.2-1.5μm The top crystalline ZnO layers showed a thickness of0.5μm,1.0μm and1.5μm for the applied potentials of−1.0V,−1.1V and−1.2 V.It indicated that the applied potentials exhibited more inﬂuence on the morphology and structures of top layer of ZnOﬁlms.The deposition of ZnO in the early stage generated large amounts of ZnO nanocrystals inside of the hydrogel networks and thenﬁlling in the bottom PHEMA layer.The former stage creates a compact bottom ZnO/PHEMA layer,while the following growth of ZnO nanocrystals out of the compact layer results in the formation of hierarchical nanos-tructures of porousﬂakes and pillars structures.High negative voltage can liberate more hydroxide ions and zinc ions in electrolyte readily diffused to or adsorbed on the cathode surface due to strong electricJournal of The Electrochemical Society,160(4)D156-D162(2013)D159Figure5.Variation curves of the cathodic current density as the function of the deposition time for ECD of ZnOﬁlms at70◦C under−1.1V from 0.001M Zn(NO3)2solution on(a)ITO and(b)500-nm-thick PHEMA coated ITO substrates.Insert images shows the top-view SEM images of the ZnO nanostructures deposited on(a)ITO and(b)500-nm-thick crosslinked PHEMA coated ITO substrates.Scale bar=1μm.ﬁeld intensity which catalyzed the electrodeposition process.31When high electrodeposition voltages of−1.2V were applied,nanocrys-tals stacking along one preferential direction may dominate the ZnO deposition,thus leading to the appearance of ZnO pillars.Electrodeposition of ZnO is based on the generation of OH-ions at the surface of working electrode by electrochemical cathodic reduc-tion of precursors such as O2,NO3−and H2O2in zinc ions aqueous solution.32In our experiments,ZnOﬁlms were cathodically deposited from zinc nitrate solutions.The zinc nitrate solution can act as both the zinc and oxygen precursor.The general scheme of electrodeposi-tion of ZnO from aqueous zinc nitrate solution is supposed as follows (Eqs.1–4):Zn(NO3)2→Zn2++2NO−3[1]NO−3+H2O+2e−→NO−2+2OH−[2]Zn2++2OH−→Zn(OH)2[3]Zn(OH)2→ZnO+H2O[4] Cathodic electrochemical reduction of nitrate to nitrite is catalyzed by Zn2+ions that are adsorbed on the surface of the cathode and liber-ates hydroxide ions,as in Eqs.1.Then,zinc ions precipitate with the hydroxyl anions,resulting in the formation of zinc hydroxide.Subse-quently,zinc hydroxide spontaneously dehydrates into zinc oxide at a slightly elevated temperature of about60◦C.33Finally,these series of multi-step reactions can be summarized by Eq.5.Zn2++NO−3+2e−→ZnO+NO−2[5] The water adsorption and swelling properties make crosslinked PHEMA hydrogel a good candidate for the modiﬁcation of working electrodes.Figure5presents the typical variation curves of the ca-thodic current density as the function of the deposition time for ECD of ZnOﬁlms on ITO and PHEMA hydrogel coated ITO substrates at 70◦C under a constant deposition potential of−1.1V from0.001M Zn(NO3)2solution.Figure5curve a represents the variation of current density with time for ECD of ZnOﬁlms on ITO substrate.It shows a rapid increase of current density to a value of−0.5mA/cm2in the ﬁrst100s,corresponding to the nucleation stage of ZnO crystallites. Then after400s the stable current density corresponds to growth of ZnO nanostructures.The insert SEM image of Figure5a shows a clear morphology of ZnO nanorod arrays grown on the ITO substrate after1000s electrodeposition.Curve b in Figure5shows a nearly linear increase of current density until600s then the current density kept stable at a value of−0.5mA/cm2.The lower current density of the sample deposited on PHEMA hydrogel in curve b shows the ZnO crystallization process is slower than that on pure ITO substrates. Even the current density value at1000s for PHEMA coated substrate is lower than the value of100s for ITO substrate.It indicates the ZnO crystallites grown inside of the PHEMA hydrogelﬁlm are still in the nucleation stage.The inset SEM image of Figure5b shows a smooth and compact surface with no obvious ZnO structures found on the ZnO/PHEMA compositeﬁlms similar to the morphology of the pure PHEMAﬁlm before electrodeposition.The effect of substrates on the current density and surface mor-phology of electrodeposited ZnOﬁlms show that there is a different formation mechanism of ZnO nanostructures on the PHEMA coated electrode.The current density increases rapidly on the ITO substrate in theﬁrst100s due to the fast reduction rate of nitrate ions to OH ions on the total ITO electrode surface.Then Zn2+ions in the vicinity of working electrode react with OH-ions,leading to the fast precipi-tation of ZnO on the ITO electrode surface and then following rapid growth of ZnO nanorod arrays.For PHEMA coated ITO electrode,as the concentration of zinc nitrate decreased to only0.001M,the zinc ions diffusion in PHEMA hydrogel was limited.Only a small amount of zinc ions could arrive at the electrode surface.The electrochemi-cal reduced OH−ions wouldﬁrst interact with the Zn ions that have diffused near the ITO surface.Similarly,the hydroxyl ions formed at the electrode surface also diffused into the PHEMA network and interacted with the zinc ions.The carbonyl groups and free hydroxyl groups present in the hydrogel give a number of sites where both the Zn and OH−can signiﬁcantly interact,slowing diffusion and reactiv-ity.The ZnO nucleation starts either at the ITO surface or within the PHEMA network near the ITO substrate.Accordingly,the growth of ZnO nanostructures is relatively slow due to the interaction of zinc and OH−ions in the PHEMA hydrogelﬁlms.In order to investigate the growth process of ZnO/PHEMA hy-bridﬁlms,a series of samples were obtained by electrodeposition at70◦C under−1.1V on500-nm-thick crosslinked PHEMA hydro-gel coated ITO substrates in0.01M Zn(NO3)2solutions for400s, 600s and1000s.For comparison,some electrodeposited samples were calcined at500◦C for2h in air to remove the polymer phase. Figure6shows the top-view and cross-section SEM images of elec-trodeposited ZnO/PHEMAﬁlms and Figure7present the surface morphologies of these ZnOﬁlms after calcination.As shown in Figure6a and6b,after electrodeposition for400s,the single layer of PHEMA/ZnO compositeﬁlm had aﬂat surface morphology.It is still in the nucleation stage of the ZnO nanoparticles within the PHEMA networks.Figure7a and7b show the morphology and struc-tures of400s deposited ZnOﬁlms after2h calcination.Irregular micro-scale cracks were found on the surface of porous ZnOﬁlm com-posed of dispersed nanoparticles.For the samples obtained after600s electrodeposition,worm-like ZnO structures were found with width of300-500nm protruded out of the compact PHEMA/ZnO layer (Fig.6c–6d).It can be seen that the ZnOﬁlm consisted of vertically connected nanocrystals with the worm-like structures on top of the ﬁlm.The ZnOﬁlm electrodeposited for1000s shows a rough surface consisted of particles andﬂakes(Fig.6e–6f).After calcination,the ZnOﬁlms can be distinguished as dual layer structure(Fig.7e–7f). This indicates that by increasing the deposition time,the ZnO depo-sition appears to follow the pathway ofﬁlling in the bottom PHEMA layer and growing out of the PHEMA/ZnO composite layer and form-ing a pure ZnO top layer by nanocrystals stacking.XPS measurements were performed to investigate the distribution of elements in the ZnO/PHEMA hybridﬁlms.Figure8shows XPS survey spectra obtained for above mentioned ZnO/PHEMA compos-iteﬁlms electrodeposited at the growth stages of400s and1000s. Zn2p,C1s,O1s and Si1s were observed in the400s electrodeposited ZnO/PHEMAﬁlms and the peak positions of Zn2p3/2,Zn2p1/2and O1s,C1s are in good agreement with the reported values.34,35TheD160Journal of The Electrochemical Society ,160(4)D156-D162(2013)Figure 6.Top-view and cross-section SEM images of ZnO ﬁlms electrode-posited at 70◦C under −1.1V on 500-nm-thick PHEMA hydrogel coated ITO substrates in 0.01M Zn(NO3)2solutions for (a,b)400s,(c,d)600s and (e,f)1000s.Scale bar =1μm.Figure 7.Top-view and cross-section SEM images of ZnO/PHEMA hybrid ﬁlms calcinated at 500◦C for 2h.The ZnO ﬁlms were obtained by electrodepo-sition at 70◦C under −1.1V on 500-nm-thick PHEMA hydrogel coated ITO substrates in 0.01M Zn(NO 3)2solutions for (a,b)400s,(c,d)600s and (e,f)1000s.02004006008001000bO K L LZ n L M M 2Z n L M M 1Z n L M MZ n 3dZ n 3pZ n 3sC 1sZ n 2p 1Z n 2p 3I n t e n s i t y (a .u .)Binding Energy (eV)O 1saFigure 8.XPS survey spectra for the ZnO/PHEMA composite ﬁlms electrode-posited at 70◦C under −1.1V on PHEMA hydrogel coated ITO substrates in 0.01M Zn(NO 3)2solution for (a)400s and (b)1000s.XPS survey spectra for 1000s ZnO ﬁlm shows prominent Zn 2p and O 1s features.The intensity of the Zn 2p peaks here are stronger than those of 400s ZnO ﬁlm.From the SEM image in Figure 6e and Figure 7e ,we know that the strong signal for 1000s sample is com-ing from the top layer of ZnO crystalline nanostructures.The minor carbon (C 1s)feature is also observed and is due to the surface con-taminants arising from the sample collection and handling.XPS depth proﬁles measurements were simultaneously performed to get information on the distribution and the chemical state of zinc.Electrodeposited ZnO/PHEMA ﬁlms were sequentially etched by Ar +ions for every 30s and 480s in total.XPS spectra were recorded after each sputtering step.The relative atomic concentration of zinc,carbon,oxygen and silicon was evaluated from the Zn 2p3,O 1s,C 1s,and Si 2s core level XPS spectra.In 3d spectra were also recorded after 480s sputtering for all samples and no signal from the ITO substrate were detected by XPS.For the ZnO/PHEMA composite ﬁlm electrodeposited for 400s,a continuous increase of Zn and O concentration was observed while the carbon concentration gradually decreased with sputtering time (Fig.9a ).The trace amount of Si corresponds to the silane crosslinking agent in the PHEMA networks.Also noted is the presence of carbon on the surface of ZnO ﬁlm deposited for 1000s (Fig.9b ).The carbon concentration sharply decreased with increasing sputtering time and dropped below the detection limit after Ar +ion sputtering for 240s.As noted earlier,this carbon is due to surface contamination during sample handling in air.As indicated in Figure 9b ,signiﬁcant amounts of Zn ions were present after 120s sputtering of outer contamination layer.After 300s sputtering,there is only Zn and O left suggesting a deposited layer of zinc oxide.The Zn/O ratio was 1.2after Ar +ion sputtering for 180s and was 1.19after 480s sputtering.This indicated that the composition of the ZnO ﬁlm is not completely stoichiometric with oxygen deﬁciency.From above results and discussion,we propose a possible mecha-nism for the formation and growth of ZnO hierarchical nanostructures electrodeposited on the PHEMA hydrogel coated electrode.Figure 10shows the schematic diagram for the formation and growth process.Firstly,the PHEMA hydrogel ﬁlm on the substrate swells while im-mersed into the zinc nitrate electrolyte.The water permeable nature of PHEMA hydrogel ﬁlm enables Zn 2+and NO 3−ions diffuse into the interior of PHEMA hydrogel ﬁlm.The positively charged zinc cation is distributed throughout and loosely bound with the carbonyl and hydroxyl groups within the PHEMA networks due to electrostatic interactions.。

210978019_高岭土负载氧化锌／氧化钛制备光催化功能材料的研究

2010年第2期【试验研究】中国非金属矿工业导刊总第81期高岭土负载氧化锌/氧化钛制备光催化功能材料的研究钱红梅1，李燕2，郝成伟1（1.皖西学院城市建设与环境系，安徽六安 237012；2.安徽建筑工业学院材料科学与工程系，安徽合肥 230022）摘要：以硫酸钛、硫酸锌、高岭土、尿素、无水乙醇等为原料，水热法制备了氧化锌/氧化钛复合纳米粉体以及高岭土负载纳米氧化锌/氧化钛复合粉体；利用X-射线衍射(XRD)对所得粉体进行了表征；研究了不同粉体对甲基橙溶液的光催化降解效果，制备出了光催化性能良好的高岭土负载纳米氧化锌/氧化钛复合粉体。

关键词：纳米粉体；高岭土；负载；水热法；光催化中图分类号：P619.232;TB332文献标识码：A文章编号：1007-9386(2010)02-0018-04Research on Preparation of Kaolin ZnO/TiO2 Load Photocatalytic Functional MaterialsQian Hongmei1, Li Yan2, Hao Chengwei1(1.Department of City Construction and Environment, West Anhui University, Liuan 237012, China; 2.Department of Materials Science and Engineering,Anhui Institute of Architecture and Industry, Hefei 230022, China)Abstract: Nano-sized ZnO/TiO2 composited and kaolin loaded ZnO/TiO2 composited were synthesized by hydrothermal method with Ti(SO4)2, ZnSO4·7H2O, kaolin, urea, ethanol, etc. The final powders were characterized by X-ray diffraction(XRD), and the photocatalytic degradation of methyl orange(MO) solution by using different powders has been studied, and a good photocatalytic properties of nano-kaolin loaded ZnO/TiO2 composited powders were prepared.Key words: nano-powder; kaolin; load; hydrothermal method; photocatalysis1 引言纳米级ZnO是一种新型高功能精细无机材料，由于颗粒尺寸的细微化，使得纳米ZnO产生了其本体块状材料所不具备的表面效应、小尺寸效应、量子效应和久保效应等[1-3]，与普通ZnO相比，纳米ZnO展现出许多特殊的性能，如无毒和非迁移性、荧光性、压电性、吸收和散射紫外线能力。

10电沉积种子层化学控制生长氧化锌纳米棒和纳米管

收稿日期：2009-01-09。

收修改稿日期：2009-04-09。

中国博士后科学基金(No.20080440674)、教育部科学技术研究重点项目(No.208008)、天津市高等学校科技发展基金计划项目(No.20071204)、建设部科技计划项目(No.2007-K1-30)资助。

＊通讯联系人。

E -mail ：tjulzf@第一作者：刘志锋，男，32岁，博士后，副教授；研究方向：功能薄膜材料、新能源材料。

电沉积种子层化学控制生长氧化锌纳米棒和纳米管刘志锋＊,1,2雅菁2鄂磊2(1天津大学化工学院，天津300072)(2天津城市建设学院材料科学与工程系，天津300384)摘要：采用水溶液法在电沉积的ZnO 种子层上制备了高度取向的ZnO 纳米棒阵列，并通过碱溶液化学腐蚀法获得了ZnO 纳米管。

对ZnO 纳米棒和纳米管的溶液生长和腐蚀过程进行了分析。

结果表明，种子层的结构和性能对ZnO 纳米棒有着重要的影响，在-700mV 电位下沉积的种子层薄膜均匀性好，生长的纳米棒密度大、与基底垂直性好；碱溶液对纳米棒的腐蚀具有选择性，通过控制腐蚀液的浓度和时间，可获得中空的ZnO 纳米管。

关键词：ZnO ；纳米棒；纳米管；水溶液法；腐蚀中图分类号：O614.24＋1文献标识码：A文章编号：1001-4861(2009)06-0995-05Controlled Growth of ZnO Nanorods and Nanotubes by ChemicalMethod on Electrodeposited Seed LayerLIU Zhi -Feng ＊,1,2YA Jing 2E Lei 2(1School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072)(2School of Materials,Tianjin Institute of Urban Construction,Tianjin 300384)Abstract:Highly oriented ZnO nanorod arrays on electrodeposited ZnO -coated seed layers were fabricated by aqueous solution method.The ZnO nanotube arrays could be obtained after chemical etching of as -prepared nanorod arrays using alkaline solution at low temperature.The growth and etching process of nanorods and nanotubes were also analyzed.The results show that the structure and property of seed layers play important roles on the morphology of ZnO nanorods.The seed layer deposited at -700mV has evenly distributed crystallites,the density of the resultant nanorods is high and ZnO nanorods stand completely perpendicular onto substrates.There was a selective etching of alkaline solution on nanorods.And,the center hollow ZnO nanotubes could be obtained after chemical etching by controlling the concentration of alkaline and etching time.Key words:zinc oxide;nanorod;nanotube;aqueous solution method;etching氧化锌(ZnO)是一种宽禁带Ⅱ-Ⅵ族半导体材料，具有优异的压电和光电特性，如高的激子束缚能、良好的机电耦合性、较低的电子诱生缺陷等。

sol-gel方法。。

Enhanced photo-induced hydrophilicity of the sol –gel-derived ZnO thin films by Na-doping (溶胶凝胶法制得的钠掺杂的ZnO 薄膜的光诱导亲水性)摘要:具有不同钠/锌比值的钠掺杂ZnO 薄膜采用溶胶凝胶法制得。

薄膜的微观结构，化学成分，表面形貌，以及薄膜的可湿性可通过X -射线衍射，X 射线光电子能谱（XPS ），扫描电镜和水接触角装置进行观察。

薄膜的润湿性和钠 /锌比值关系已详细研究。

通过交替紫外线水性随着薄膜钠/锌比值增加到高达0.08，然后下降。

该机制可能是由于表面纳米结构和钠的掺杂浓度诱导。

通过溶胶凝胶法在石英玻璃和硅衬底上生长钠掺杂的ZnO 薄膜钠掺杂氧化锌薄膜制备方法：乙二醇甲醚和乙醇胺分别被用作溶剂和稳定剂。

二水醋酸锌（Zn(CH3COO)2·2H2O ）在室温下溶解于乙二醇甲醚和乙醇胺混合物中。

乙醇胺和醋酸锌的摩尔比为1:1，醋酸锌浓度为0.5 mol/ L 。

不同数量的氯化钠被加到上述的溶解物中，钠/锌的原子比分别为0，0.02，0.04，0.08和0.10（这些薄膜分别命名为氧化锌，氧化锌：钠 2％，氧化锌：钠 4％，氧化锌：钠8％，与ZnO ：Na 10％）。

溶解物在60◦ç被搅拌120分钟，在此过程中使用磁力搅拌器来获得清晰，均匀透明溶胶，作为溶胶涂层后维持一天。

石英玻璃和硅被用来作为衬底。

氧化锌薄膜通过一个转速为3000rpm 自旋涂层法自旋30秒获得。

凝胶薄膜在150◦C 温度下被干燥10分钟，此过程重复10次。

这些涂层薄膜在800◦C 的空气中退火处理60分钟。

第一步：获得溶解物第二步：二水醋酸锌（Zn(CH3COO)2·2H2O）溶解乙二醇甲醚和乙醇胺混合物乙醇胺和醋酸锌的摩尔比为1:1，醋酸锌浓度为0.5 mol/ L2、Effects of substrates and seed layers on solution growing ZnO nanorods （衬底和籽晶层对熔融法制的ZnO 纳米棒的影响）摘要：定向ZnO 纳米棒通过二阶段法制得，包括低温条件下在硝酸锌和六次甲基四胺水溶液中不同衬底籽晶层的合成和氧化锌纳米棒的生长。

Growth and photocatalytic properties of one-dimensional ZnO nanostructures prepared by thermal evapo

Growth and photocatalytic properties of one-dimensional ZnO nanostructures prepared by thermal evaporationHongwei Yan a ,Jianbo Hou a ,Zhengping Fu a ,Beifang Yang a ,*,Pinghua Yang a ,Kaipeng Liu a ,Meiwang Wen a ,Youjun Chen a ,Shengquan Fu b ,Fanqing Li ba Department of Materials Science and Engineering,University of Science and Technology of China,Hefei,Anhui 230026,PR China bStructure Research Laboratory,University of Science and Technology of China,Hefei,Anhui 230026,PR China1.IntroductionZnO is a wide band-gap (3.37eV)semiconductor with a high exciton binding energy of 60meV at room temperature,which exhibits semiconducting and piezoelectric dual properties [1].One-dimensional ZnO nanostructures have been extensively studied by many researchers due to their unique properties,which have novel applications in room-temperature ultraviolet laser,gas sensors and biomedical sciences [2–4].Recently the photocatalytic performance of ZnO has attracted much attention which was considered as an alternative to TiO 2[5–7].Though TiO 2has been thought to be the most excellent semiconductor photocatalyst,ZnO is still worth to be investigated which has even higher photocatalytic efﬁciency compared to TiO 2in the treatment of some organic pollutants [8–12].Nanoparticles with higher photocatalytic efﬁciency than their bulk phase counterparts were extensively applied in the photo-catalytic reactions,as which have effective separation of electron–hole pairs and broadened band-gap from quantum size effects [13].However,there are some drawbacks for nanoparticles such as the tendency to aggregate during aging and difﬁculty in separation and recovery from solutions,which greatly limit their extensive applications.A good solution is the immobilization of semicon-ductor photocatalysts on the substrates.When semiconductor nanoparticles were immobilized on the substrates,the surface-to-volume area of photocatalysts will be decreased resulting in the reduction of photocatalytic efﬁciency.It is a challenge to synthesize a photocatalyst which not only is immobilized on the substrate but also has high photocatalytic efﬁciency.The synthesis of one-dimensional nanostructure ﬁlms is prospective to overcome the above-mentioned drawbacks.Recently various types of ZnO nanostructures have been investigated in the photodegradation of organic contaminants,which were synthesized by the various fabrication techniques [14–17].However,there is still a need to track the kinetics of photocatalytic process and the photocatalytic stability of nanostructured ZnO for its practical applications.Moreover,the growth mechanism of the ZnO nanorods and nanotubes is also open to question.In this paper,aligned ZnO nanorods and nanotubes on the silicon substrates were synthesized by thermal evaporation of high pure Zn powders without using any other metal catalyst.The morphology evolution of the nanostructures with prolonged growth time was studied.ZnO nanoneedle and nanoparticle ﬁlms were also grown on even larger size silicon wafers,and their photocatalytic and recycle performances were studied in detail.2.ExperimentalThe ﬁlms were deposited on the (100)oriented n-type silicon wafers in two sizes:7mm Â20mm and 20mm Â20mm.BeforeMaterials Research Bulletin 44(2009)1954–1958A R T I C L E I N F O Article history:Received 30September 2008Received in revised form 5June 2009Accepted 25June 2009Available online 5July 2009Keywords:A.Nanostructures A.SemiconductorsB.Vapor depositionC.Electron microscopyD.Catalytic propertiesA B S T R A C TAligned ZnO nanorods and nanotubes were grown on the silicon substrates by thermal evaporation of high pure zinc powders without any other metal catalyst.The morphology evolution of ZnO nanostructures with prolonged growth time suggested that the growth of the ZnO nanorods and nanotubes follows the vapor–liquid–solid mechanism.ZnO nanoneedle and nanoparticle ﬁlms were also synthesized by the same way,and their photocatalytic performances were tested for the degradation of organic dye methylene blue.The ZnO nanoneedle ﬁlms exhibited very high photocatalytic activities.The decomposition kinetics of the organic pollutant was discussed.Moreover,it is found that the ZnO nanoneedle ﬁlms showed very stable photocatalytic activity.ß2009Elsevier Ltd.All rights reserved.*Corresponding author.Tel.:+865513603194;fax:+865513601592.E-mail address:bfyang@ (B.Yang).Contents lists available at ScienceDirectMaterials Research Bulletinj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /m a t re s b u0025-5408/$–see front matter ß2009Elsevier Ltd.All rights reserved.doi:10.1016/j.materresbull.2009.06.014use,the wafers were ultrasonically cleaned in acetone,ethanol and distilled water in sequence,and then were boiled for10min in the solutions of NH3ÁH2O:H2O2:H2O(1:1:3)and HCl:H2O2:H2O(3:1:1), respectively.Then the wafers were etched by HF acid and washed with distilled water and dipped in ethanol until it was used.The silicon wafers with polished face downward were laid on a quartz boat in which0.4g high purity zinc powders(99.99%)were loaded. The vertical distance of the zinc powders and the silicon substrates was about2mm.A horizontal tube furnace was heated to the reaction temperature and evacuated using a mechanical pump and then purged with pure argon gas.After the quartz boat was loaded into the furnace,a mixture of4%O2in Ar(20sccm)and pure argon gas(30sccm)was introduced.After deposition for a certain time, the quartz boat was taken out from the tube and a white/gray layer was formed on the silicon substrate.The X-ray diffraction patterns were recorded on a Philips X’pert prosuper diffractometer using Cu K a irradiation(l=1.5419A˚).The morphologies of the products were analyzed byﬁeld emission scanning electron microscopy (FESEM)(JSM-6700F).The photocatalytic degradation of organic dye methylene blue (MB)(10mg/L)was executed under irradiation by a20W low-pressure mercury lamp with main wavelength of254nm.The photocatalytic activities of the depositedﬁlms were tested as following methods:(1)dynamic:the ZnOﬁlms were suspended in 60mL MB solution with magnetic stirring and a certain amount of solution was taken out every30min,which was then analyzed by absorption spectra on an ultraviolet-visible recording spectro-photometer(Shimadzu UV-2401);(2)static:the ZnOﬁlms were dipped in8mL MB solution without magnetic stirring under2h irradiation,and then the solution was tested.This photocatalytic degradation test was repeated13times on the same sample for detecting the photocorrosion of ZnO.And the sample did not display an apparent surface change after the whole test.3.Results and discussionGenerally,the vapor–liquid–solid(VLS)and vapor–solid(VS) processes are used to interpret the growth mechanism of one-dimensional(1D)nanostructures[18–21].Under the existence of some metal catalysts such as Au,Pt,and Sn,etc.,the growth of1D ZnO nanostructures usually follows the VLS mechanism.In this process,a droplet of liquid alloy will form and guide the anisotropic crystal growth.The existence of nanoparticles capping at the end of a1D nanostructure is a characteristic of the VLS mechanism.When no metal catalysts are used,the VS process is conventionally used to interpret the growth mechanism of1D ZnO nanostructures in our experiment.To prove this VS mechanism, reaction time-dependent experiments were carried out.Fig.1displays the morphologies of the ZnOﬁlms grown on the substrate of7mmÂ20mm in size at6208C at different times: 10min,20min and30min.It is clearly seen that a morphology evolution has occurred with increasing the growth time.For the sample grown for10min,vertically aligned nanorods were formed with some particles capping on their tips.When growingforFig.1.The low and high magniﬁcation SEM images of the ZnOﬁlms grown on the silicon substrates at6208C at different times:(a and b)10min;(c and d)20min;(e and f) 30min.H.Yan et al./Materials Research Bulletin44(2009)1954–1958195520min,the capping particles on the tips of the nanorods decreased gradually and a concaved surface was formed.When extending the growth time to 30min,a mass of nanotubes were formed mixed with few nanorods.As seen from the high magniﬁcation SEM images,the walls of the nanotubes are not smooth and capped by some particles.The diameter of the nanotubes decreases from the root to the tip.A typical XRD pattern of ZnO nanorods was shown in Fig.2.All the strong peaks can be readily indexed to hexagonal wurtzite ZnO with cell constants comparable to the reported data (JCPDS 89-0511).The higher intensity of (002)peak relative to other peaks exhibits high c -axis growth orientation of the ZnO nanorods.As seen from Fig.1a the top surface of the nanorods is not smooth or faceted which is different from the conventional morphology of the nanorods prepared by this method.It should be noted that the surface capped by nanoparticles still exists in the nanotubes.In our experiments no metal catalysts were intention-ally introduced.However,considering that the melting point of pure metal zinc is 4198C at atmospheric pressure,it is implied that the droplet of liquid Zn would emerge on the silicon substrate at the growth temperature of 6208C.The liquid Zn is the Zn source of ZnO as well as being a self-catalyst in the growth process.A liquid phase Zn/ZnO x (x <1)would form at the early stage when oxygen gas was adsorbed on liquid Zn [22].The highly reactive liquid droplet was quickly oxygenated and nucleated into nanoparticles,and then grew orientedly into nanorods.The evaporated Zn vapor and ﬂowing O 2gas would continuously adsorb on the surface of liquid droplet and supply the growth of nanorods.As increasing the growth time,the morphology of top surface transformed from nanoparticles to concave surface and then to nanowalls.In theprevious reports,Mo et al.has demonstrated a similar morphology transform from ZnO nanorods to microhemispheres and nano-tubes under hydrothermal conditions [23,24].They proposed a growth mechanism in which the ‘‘mother’’rods may attach the tiny rods at high surface-energy growing fronts and grow larger.In our work,as increasing the growth time,the decreasing concentration of Zn vapor lead to a selective deposition of ZnO nanoparticles on the high energy surface of ZnO nanorod top,and then the concave top surface was formed.Moreover,as further increasing the growth time the partial pressure of Zn vapor decreased as a result of the consumption of reaction materials,which resulted also in the formation of a thin wall on the top of nanorods.Thus,the morphology of top surface of ZnO changed from nanoparticles to concave surface and then to nanowalls.The morphology evolution process of ZnO nanostructures with prolonged growth time suggested that the growth of the ZnO nanorods and nanotubes follows a self-catalytic vapor–liquid–solid mechanism [25].Although the formation process of the tubes is deduced,the intrinsic cause of the shape transformation from rod to tube is still unclear.In addition,in view of the high vapor pressure of Zn metal ($10Torr at 6008C),the concave morphology may also originate from re-evaporation of Zn element,which is rich in ZnOx.The mechanism described above needs to be examined and improved by more studies.For the photocatalytic tests of the ZnO ﬁlms,the larger size wafers were used.Fig.3displays the morphologies of the ZnO ﬁlms grown on the substrate of 20mm Â20mm in size at two growth temperatures for 30min:6208C and 6508C,respectively.When the substrates were changed from small size to large size,the surface morphologies of the deposited ﬁlms have changed very much.As shown in Fig.3a,the ﬁlm grown at 6208C is composed of a mass of poorly aligned nanoneedles.On the edge of the ﬁlm,there exist some aggregated nanoparticles.As compared with it,the ﬁlm grown at 6508C (Fig.3b)is mainly composed of loose nanopar-ticles on a compact nanoparticle pared to the 7mm Â20mm wafer,the growth control of ZnO nanostructures on the 20mm Â20mm wafer becomes more difﬁcult.The possible reasons are that the morphology of the nanostructures is inﬂuenced by many experimental parameters,including reaction temperature,the distance between the source material and the substrate,vapor dynamics,oxidation rate,etc.[26].These factors may result in the big difference of the surface morphologies of ZnO nanostructures with dissimilar sizes substrates.The nanoneedles grown on the 20mm Â20mm wafers looks disorderly that maybe the result of the above-mentioned factors.Though aligned nanorods have more anticipation on the photocatalysis than the disorderly grown nanoneedles,the latter was tested in our photocatalysis experiments in view of the synthetic facility.Fig.4shows the photocatalytic activities of different photo-catalysts including ZnO nanoneedles,nanoparticles,TiO 2ﬁlms and ﬂowerlike ZnO nano/microstructures.TiO 2ﬁlms weresynthesizedFig.2.A typical XRD pattern of the ZnO nanorods grown on the silicon substrates at 6208C.Fig.3.The SEM images of ZnO nanoneedle (a)and nanoparticle (b)ﬁlms.H.Yan et al./Materials Research Bulletin 44(2009)1954–19581956by a sol–gel dip-drawing process and annealed in air at 5008C for 2h.Flowerlike ZnO nano/microstructures were prepared by a hydrothermal method and annealed in air at 3008C for 1h [27].All the samples were the same in size and tested under the same conditions.As a comparison,a blank silicon wafer of 20mm Â20mm in size was used as the reference sample for testing the inﬂuence of the ultraviolet lamp on the degradation of MB.After 3h irradiation under ultraviolet light without photo-catalysts,the degradation ratio of MB is about 15%,which is 96%,75%,62%and 56%for the ZnO nanoneedles,nanoparticles,TiO 2ﬁlms and ﬂowerlike ZnO during the same time.The ZnO nanoneedles display much better photocatalytic activity than the other samples.Moreover,the samples synthesized by thermal evaporation show the distinct advantages in the degradation of organic pollutants.It may be a result of the higher separation efﬁciency of electron–hole pairs in the ZnO nanostructures with high crystallinity synthesized by thermal evaporation.Without magnetic stirring the diffusion of MB molecules in solution is an important rate-controlled process.This is conﬁrmed by the fact that the color of solution became deep gradually far from the ZnO ﬁlms after the photocatalytic reaction in the static mode.Under magnetic stirring the MB solution was uniformly dispersed,and the reaction rate was controlled by the surface reaction process on the ZnO ﬁlm.The decomposition of organiccompounds by photocatalysts is a solid–liquid interface process,and the reactions take place at the surface of the photocatalyst.The Langmuir–Hinshelwood (LH)model has been shown to success-fully describe the heterogeneous photocatalytic degradations of organic pollutants in previous works [6,28–30].The reaction rate is proportional to the fraction of the surface covered by the reactant in terms of the LH model,which could be deﬁned as following [31]:r ¼ÀdC ¼k u ¼kKC(1)where r is the reaction rate,C is the equilibrium concentration of organic pollutants,t is the time,k is the rate constant,u is the fraction of the surface covered by reactants,and K is the adsorption equilibrium constant.When the concentration of organic com-pounds is very high (KC )1)or very low (KC (1),the equation (1)can be simpliﬁed to a zero order reaction (ÀdC /dt =k )or a pseudo-ﬁrst reaction (ÀdC /dt =kKC ).In our system it was found that the experiment data presented in Fig.6could not be ﬁtted very well only by zero order or pseudo-ﬁrst order reaction.By integration of Eq.(1)we got the following expression:KC 01ÀC C 0 Àln CC 0¼kKt(2)C 0is the initial concentration of organic pollutants.By takingC 0=10mg/L and ﬁtting the experimental data in Fig.5(the solid lines),we obtained k 1=0.107mg/(L min)(2.86Â10À7M/min),K 1=0.116L/mg (4.34Â104M À1)for nanoparticles,andk 2=0.140mg/(L min)(3.74Â10À7M/min),K 2=0.225L/mg(8.41Â104M À1)for nanoneedles.It reveals that the ZnO nanoneedle ﬁlms have the faster reaction rate and higher adsorption ability than the nanoparticle ﬁpared with the ZnO nanoparticle ﬁlms in the same size,the ZnO nanoneedle ﬁlms have higher speciﬁc surface area which could adsorb more MB molecules.When the ultraviolet light irradiated on the ﬁlms,the ZnO nanoneedles could harvest more light and generate more electron–hole pairs resulting in a higher reaction rate.As a result,the ZnO nanoneedle ﬁlms exhibited higher photocatalytic activity than the nanoparticle ﬁlms under the same initial concentration of MB.Furthermore,the experimental results of Yi and co-workers revealed recently,that the increase in aspect ratio of TiO 2nanorods resulted in the effect of reduction of e À/h +recombination [32].In our samples,the aspect ratio of the ZnO nanoneedles was obviously larger than that of the ZnO nanoparticles,thus it should induce a higher photocatalytic activity for the ZnOnanoneedleFig.5.Variation with time of the relative concentration of methyleneblue.Fig.4.The decomposition ratio of methylene blue withtime.Fig.6.The decomposition ratio of methylene blue vs.the repeated test times.H.Yan et al./Materials Research Bulletin 44(2009)1954–19581957ﬁlms than the nanoparticleﬁlms.Moreover,the aggregation of nanoparticles on the substrate decreased their speciﬁc surface area,which would result in the relative lower photocatalytic efﬁciency of the nanoparticleﬁlms.These results indicate that the synthesis of one-dimensional ZnO nanostructureﬁlms is an effective way to prepare immobilized photocatalysts with high photocatalytic activity.The photocatalytic stability of the ZnOﬁlms is an important concern for the repeated use of the photocatalysts.ZnO will dissolve in both acidic and highly alkaline conditions,and it will also dissolve in neutral solution under light illumination[10].A disadvantage for ZnO photocatalyst is the photocorrosion induced by photogenerated holes.This process can be described by the following reaction equation[10]:ZnOþ2h v bþ!Zn2þþOÃwhere h vb+is the hole in the valence band,and O*is an intermediate oxygen species with high reaction activity.The above-mentioned disadvantages do not imply the decrease of the photocatalytic activity of ZnO according to previous works [10,33,34].Without a doubt,the photocorrosion is unfavorable to the recycle use of the photocatalysts.Interestingly,our ZnO nanoneedleﬁlms are relative stable against photocorrosion,unlike traditional ZnO powder photocatalysts.As shown in Fig.6,the ZnO nanoneedleﬁlm does not exhibit any great loss in activity even after13times cycles for the degradation of MB in the static mode condition.Some researchers have recently found that the photocorrosion of ZnO can be successfully inhibited via hybridiza-tion with other material,such as monolayer polyaniline[35], graphite-like carbon[36],perﬂuorinated ionomer[37],and so on. However,both photocatalysis and photocorrosion are very complex processes,and the photocatalytic activity of the ZnO nanoneedleﬁlms may depend on,for example,their aspect ratio of nanoneedle,size distribution,and/or surface/bulk compositions. Therefore,the detailed mechanism for the enhanced photocata-lytic activity and stability of the1D ZnO nanostructures is still an open question.4.ConclusionsIn conclusion,aligned ZnO nanorods and nanotubes were grown on the silicon substrates by a simple thermal evaporation process.The growth and morphology evolution of the ZnO nanostructures were interpreted by a self-catalytic vapor–liquid–solid mechanism.ZnO nanoneedle and nanoparticleﬁlms were also synthesized by the same way,and their photocatalytic performance were tested by decoloring the organic dyes MB, compared with the TiO2ﬁlms andﬂowerlike ZnO nano/micro-structuresﬁlms.It was found that the ZnO nanoneedleﬁlms had much better photocatalytic efﬁciency than the other samples.The decomposition kinetics of the organic pollutant MB was well explained by the Langmuir–Hinshelwood model.The repeated photocatalytic tests conﬁrmed the long-time photocatalytic stability of the ZnO nanoneedleﬁlms,which showed a good application prospect in the treatment of organic pollutants. AcknowledgmentThis work is supported by National Natural Science Research Foundation of China.References[1]Z.L.Wang,J.Phys.:Condens.Matter16(2004)R829–R858.[2]M.H.Huang,S.Mao,H.Feick,H.Q.Yan,Y.Y.Wu,H.Kind,E.Weber,R.Russo,P.D.Yang,Science292(2001)1897–1899.[3]Q.Wan,Q.H.Li,Y.J.Chen,T.H.Wang,X.L.He,J.P.Li,C.L.Lin,Appl.Phys.Lett.84(2004)3654–3656.[4]A.Wei,X.W.Sun,J.X.Wang,Y.Lei,X.P.Cai,C.M.Li,Z.L.Dong,W.Huang,Appl.Phys.Lett.89(2006)123902.[5]T.Pauporte,J.Rathousky,J.Phys.Chem.C111(2007)7639–7644.[6]C.H.Ye,Y.Bando,G.Z.Shen,D.Golberg,J.Phys.Chem.B110(2006)15146–15151.[7]Y.Y.Wu,H.Q.Yan,P.D.Yang,Top.Catal.19(2002)197–202.[8]A.Muruganandham,N.Shobana,A.Swaminathan,J.Mol.Catal.A:Chem.246(2006)154–161.[9]S.Sakthivel, B.Neppolian,M.V.Shankar, B.Arabindoo,M.Palanichamy,V.Murugesan,Sol.Energy Mater.Sol.Cells77(2003)65–82.[10]A.A.Khodja,T.Sehili,J.F.Pilichowski,P.Boule,J.Photochem.Photobiol.A141(2001)231–239.[11]C.Lizama,J.Freer,J.Baeza,W.D.Mansilla,Catal.Today76(2002)235–246.[12]M.Fassier,N.Chouard,C.S.Peyratout,D.S.Smith,H.Riegler,D.G.Kurth,C.Ducroquetz,M.A.Bruneaux,J.Eur.Ceram.Soc.29(2009)565–570.[13]M.R.Hoffmann,S.T.Martin,W.Y.Choi,D.W.Bahnemann,Chem.Rev.95(1995)69–96.[14]J.L.Yang,S.J.An,W.I.Park,G.C.Yi,W.Choi,Adv.Mater.16(2004)1661–1664.[15]Q.Wan,T.H.Wang,J.C.Zhao,Appl.Phys.Lett.87(2005)083105.[16]J.J.Wu,C.H.Tseng,Appl.Catal.B:Environ.66(2006)51–57.[17]F.Xu,Z.Y.Yuan,G.H.Du,T.Z.Ren,C.Bouvy,M.Halasa,B.L.Su,Nanotechnology17(2006)588–594.[18]Z.L.Wang,Annu.Rev.Phys.Chem.55(2004)159–196.[19]Z.R.Dai,Z.W.Pan,Z.L.Wang,Adv.Funct.Mater.13(2003)9–24.[20]J.G.Lu,P.C.Chang,Z.Y.Fan,Mater.Sci.Eng.R:Rep.52(2006)49–91.[21]w,J.Goldberger,P.D.Yang,Annu.Rev.Mater.Res.34(2004)83–122.[22]H.J.Fan,F.Bertram,A.Dadgar,J.Christen,A.Krost,M.Zacharias,Nanotechnology15(2004)1401–1404.[23]M.Mo,J.C.Yu,L.Zhang,S.-K.A.Li,Adv.Mater.17(2005)756–760.[24]M.Mo,S.H.Lim,Y.-W.Mai,R.-K.Zheng,S.P.Ringer,Adv.Mater.20(2008)339–342.[25]J.Xiao,X.Zhang,G.Zhang,Nanotechnology19(2008)295706.[26]G.Shen,Y.Bando,B.Liu,D.Golberg,C.-J.Lee,Adv.Funct.Mater.16(2006)410–416.[27]M.Wen,B.Yang,H.Yan,Z.Fu,C.Cai,K.Liu,Y.Chen,J.Xu,S.Fu,S.Zhang,J.Nanosci.Nanotechnol.9(2009)2038–2044.[28]I.Poulios,E.Micropoulou,R.Panou,E.Kostopoulou,Appl.Catal.B:Environ.41(2003)345–355.[29]S.H.Zhou,A.K.Ray,Ind.Eng.Chem.Res.42(2003)6020–6033.[30]S.Chakrabarti,B.K.Dutta,J.Hazard.Mater.112(2004)269–278.[31]H.Al-Ekabi,N.Serpone,J.Phys.Chem.92(1988)5726–5731.[32]H.J.Yun,H.Lee,N.D.Kim,J.Yi,mun.11(2009)363–366.[33]O.A.Fouad,A.A.Ismail,Z.I.Zaki,R.M.Mohamed,Appl.Catal.B:Environ.62(2006)144–149.[34]N.Daneshvar,D.Salari,A.R.Khataee,J.Photochem.Photobiol.A162(2004)317–322.[35]H.Zhang,R.L.Zong,Y.F.Zhu,J.Phys.Chem.C113(2009)4605–4611.[36]L.W.Zhang,H.Y.Cheng,R.L.Zong,Y.F.Zhu,J.Phys.Chem.C113(2009)2368–2374.[37]H.C.Wang,P.Liu,S.M.Wang,W.Han,X.X.Wang,X.Z.Fu,J.Mol.Catal.A:Chem.273(2007)21–25.H.Yan et al./Materials Research Bulletin44(2009)1954–1958 1958。

微生物生长促进剂英语

微生物生长促进剂英语Microbial growth promoters (MGP) are substances that stimulate the growth and development of microorganisms. They are commonly used in various industries, including agriculture, food production, wastewater treatment, and pharmaceuticals. The use of microbial growth promoters has gained significant attention due to their potential benefits in enhancing productivity, improving product quality, and minimizing environmental impact. This article will provide an overview of microbial growth promoters, their applications, and their benefits.Microbial growth promoters can be classified into three main categories: probiotics, prebiotics, and synbiotics. Probiotics are live microorganisms that confer health benefits on the host when consumed in adequate amounts. They can improve digestion, boost the immune system, and enhance nutrient absorption. Common examples of probiotics include Lactobacillus and Bifidobacterium.Prebiotics, on the other hand, are non-digestible food ingredients that promote the growth of beneficial microorganisms in the gut. They serve as nourishment for probiotics and stimulate their multiplication. Inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS) are commonly used prebiotics.Synbiotics are a combination of probiotics and prebiotics. They are designed to maximize the benefits of both by delivering live microorganisms together with nutrients that promote their growth and colonization. Synbiotics can effectively modulate the gut microbiota and improve gastrointestinal health.In the field of agriculture, microbial growth promoters are used to enhance crop growth and yield. They can improve nutrient uptake, increase resistance to pests and diseases, and promote soil fertility. For example, certain bacteria, such as Azospirillum and Rhizobium, can fix atmospheric nitrogen and make it available to plants. This reduces the reliance on chemical fertilizers, resulting in cost savings and reduced environmental pollution.In the food industry, microbial growth promoters are used to improve the production and quality of various food products. They can enhance fermentation processes, manage spoilage organisms, and increase the shelf life of food. For instance, certain lactic acid bacteria are used in the production of yogurt and cheese to improve texture, flavor, and microbial safety.Microbial growth promoters also play a crucial role in wastewater treatment. They can degrade organic pollutants, remove nutrients like nitrogen and phosphorus, and improve overall treatment efficiency. Certain strains of bacteria, such as Nitrosomonas and Nitrobacter, are commonly used in biological wastewater treatment systems to convert ammonia into nitrate through nitrification.In the pharmaceutical industry, microbial growth promoters are used in the production of antibiotics, vaccines, and other biologics. They can enhance the yield and quality of microbial fermentation processes, leading to increased production efficiency and reduced costs.The use of microbial growth promoters offers several benefits. Firstly, they can improve productivity and yield in variousindustries. This leads to increased profitability and competitiveness. Secondly, they can enhance product quality by improving characteristics such as taste, texture, and safety. Thirdly, they can reduce environmental impact by minimizing the use of chemical inputs and promoting sustainable practices. Finally, microbial growth promoters can have positive health effects on both humans and animals by promoting gut health and improving disease resistance.In conclusion, microbial growth promoters are valuable substances that stimulate the growth and development of microorganisms. They have wide-ranging applications in industries such as agriculture, food production, wastewater treatment, and pharmaceuticals. The use of microbial growth promoters can lead to increased productivity, improved product quality, and reduced environmental impact. Probiotics, prebiotics, and synbiotics are common types of microbial growth promoters that offer various health and production benefits.。

氧化锌纳米结构的热蒸发沉积合成及生长机理

氧化锌纳米结构的热蒸发沉积合成及生长机理田蜜;侯丽珍;喻博闻;宋春蕊;苏耿;王世良;贺跃辉【摘要】以ZnO粉末为原料,用N 2作为载气,采用无催化辅助的热蒸发法沉积制备ZnO纳米结构,分别用X线衍射仪、扫描电镜和透射电镜对ZnO的物相、形貌和结构进行表征,并结合晶体生长理论和实验条件,对ZnO产物的形貌变化和纳米带生长方向进行研究.结果表明:离气源较近的位置到离出口较近的位置,ZnO纳米结构的形貌由连续颗粒膜逐渐向纳米带、直径大于100 nm和直径小于100 nm 的纳米线变化.特别是发现ZnO纳米带除了常见的[001]生长方向外,还有[101]和[203]两种极为罕见的生长方向,这些纳米带都具有上下表面均由(±010)晶面组成的特点.ZnO产物的形貌变化是其生长过程由动力学控制为主转向热力学控制为主的结果,纳米带生长方向不同,可能与其晶核形成过程中的竞争生长有关.【期刊名称】《粉末冶金材料科学与工程》【年(卷),期】2016(021)001【总页数】7页(P18-24)【关键词】ZnO;纳米结构;热蒸发沉积;纳米带;纳米线;生长方向【作者】田蜜;侯丽珍;喻博闻;宋春蕊;苏耿;王世良;贺跃辉【作者单位】中南大学物理与电子学院,先进材料超微结构与超快过程研究所,长沙410083;湖南师范大学物理与信息科学学院,长沙 410081;中南大学粉末冶金国家重点实验室,长沙 410083;中南大学物理与电子学院,先进材料超微结构与超快过程研究所,长沙 410083;中南林业科技大学材料科学与工程学院,长沙 410004;中南大学物理与电子学院,先进材料超微结构与超快过程研究所,长沙 410083;中南大学粉末冶金国家重点实验室,长沙 410083【正文语种】中文【中图分类】O781ZnO作为II-VI族宽禁带半导体材料, 室温下带隙为3.37 eV，具有大的激子束缚能60 meV，在室温条件下表现出近紫外光[1]和透明导电性能[2]。

Hydrothermal growth of ZnO nanostructures

Home Search Collections Journals About Contact us My IOPscienceHydrothermal growth of ZnO nanostructuresThis content has been downloaded from IOPscience. Please scroll down to see the full text.2009 Sci. Technol. Adv. Mater. 10 013001(/1468-6996/10/1/013001)View the table of contents for this issue, or go to the journal homepage for moreDownload details:IP Address: 183.237.9.101This content was downloaded on 16/04/2014 at 07:04Please note that terms and conditions apply.IOP P UBLISHING S CIENCE AND T ECHNOLOGY OF A DV ANCED M ATERIALS Sci.Technol.Adv.Mater.10(2009)013001(18pp)doi:10.1088/1468-6996/10/1/013001TOPICAL REVIEWHydrothermal growth of ZnO nanostructuresSunandan Baruah and Joydeep DuttaCentre of Excellence in Nanotechnology at the Asian Institute of Technology,PO Box4,Klong Luang,Pathumthani12120,ThailandE-mail:joy@ait.ac.thReceived5October2008Accepted for publication14November2008Published13January2009Online at /STAM/10/013001AbstractOne-dimensional nanostructures exhibit interesting electronic and optical properties due totheir low dimensionality leading to quantum conﬁnement effects.ZnO has received lot ofattention as a nanostructured material because of unique properties rendering it suitable forvarious applications.Amongst the different methods of synthesis of ZnO nanostructures,thehydrothermal method is attractive for its simplicity and environment friendly conditions.Thisreview summarizes the conditions leading to the growth of different ZnO nanostructures usinghydrothermal technique.Doping of ZnO nanostructures through hydrothermal method are alsohighlighted.Keywords:ZnO,hydrothermal,nanostructures,synthesis,doping(Someﬁgures in this article are in colour only in the electronic version)1.IntroductionNanostructured ZnO materials have received considerable interest from scientists due to their remarkable performance in electronics,optics and photonics.As early as the1960s, synthesis of ZnO thinﬁlms was an activeﬁeld because of applications in sensors,transducers and as photocatalysts.In the last few decades,study of one-dimensional material has gained importance in nanoscience and nanotechnology.With reduction in size,novel electrical,mechanical,chemical and optical properties are introduced resulting from surface and quantum conﬁnement effects.ZnO is a signiﬁcant technological material.The absence of a centre of symmetry in its wurtzite structure,along with large electromechanical coupling,results in strong piezoelectric and pyroelectric properties.ZnO is therefore widely used in mechanical actuators and piezoelectric sensors.In addition,ZnO is a wide band-gap(3.37eV) compound semiconductor that is appropriate for short wavelength optoelectronic applications.The high exciton binding energy(60meV)in ZnO crystal allows efﬁcient excitonic emission at room temperature.ZnO is transparent to visible light and its conductivity can be increased through doping.ZnO nanostructures have a wide range of high technology applications like surface acoustic waveﬁlters[1], photonic crystals[2],photodetectors[3],light emitting diodes[4],photodiodes[5],gas sensors[6],optical modulator waveguides[7],solar cells[8,9]and varistors[10].ZnO is also receiving a lot of attention because of its antibacterial property and its bactericidal efﬁcacy has been reported to increase as the particle size decreases[11].The discovery of carbon nanotubes by Iijima[12]in 1991has initiated active research leading to the growth and characterization of one-dimensional nanowires of elemental and compound semiconductors such as Si[13], Ge[14],InP[15],GaAs[16]and ZnO[17–19].Different nanostructures of ZnO have been reported such as nanowires and nanorods[20],nanocombs[21],nanorings[22], nanoloops and nanohelices[23],nanobows[24], nanobelts[25]and nanocages[26].These structures have been successfully synthesized under explicit growth conditions[27].Figure1.The wurtzite structure model of ZnO.ZnO nanostructures can be grown either in solution or from gaseous phase.The gas phase synthesis methods are expensive and complicated.The solution phase synthesis is usually done in water.The hydrothermal process of growing ZnO nanostructures has gained immense popularity due to its simplicity and tolerable growth conditions.As synthesis is carried out in aqueous solution,the growth temperatures are less than the boiling point of water.2.Zinc oxide:crystal structureThe ZnO crystal is hexagonal wurtzite and exhibits partial polar characteristics[27]with lattice parameters a=0.3296 and c=0.52065nm.The structure of ZnO can be described as a number of alternating planes composed of tetrahedrally coordinated O2−and Zn2+stacked alternately along the c-axis,as shown inﬁgure1.The tetrahedral coordination in ZnO results in piezoelectric and pyroelectric properties due to the absence of inversion symmetry.Another important characteristic of ZnO is polar surfaces.The most common polar surface is the basal plane(0001).One end of the basal polar plane terminates with partially positive Zn lattice sites and the other end terminates in partially negative oxygen lattice sites.The oppositely charged ions produce positively charged Zn-(0001) and negatively charged O-(000¯1)surfaces,resulting in a normal dipole moment and spontaneous polarization along the c-axis as well as a variance in surface energy.To maintaina stable structure,the polar surfaces generally have facets or exhibit massive surface reconstructions,but ZnO±(0001) surfaces are exceptions:they are atomicallyﬂat,stable and exhibit no reconstruction[1,2].Efforts to understand the superior stability of the ZnO±(0001)polar surfaces are at the forefront of research in today’s surface physics[3–6].The other two most commonly observed facets for ZnO are{2¯1¯10} and{01¯10},which are non-polar and have lower energy than the{0001}facets.Figure2.Growth morphologies of ZnO nanostructures with corresponding facets(reproduced with permission from[27]©2004IOP).3.Zinc oxide:growth structuresZnO exhibits a varied range of novel structures.These structures can be grown by tuning the growth rates along three fast growing directions:2¯1¯10(±[¯12¯10],±[2¯1¯10],±[¯1¯120]);01¯10(±[01¯10],±[10¯10],±[1¯100])and±[0001]. The relative surface activities of various growth facets under given conditions determine the surface morphology of the grown structure.Macroscopically,a crystal has different kinetic parameters for different crystal planes,which are emphasized under controlled growth conditions.Thus,after an initial period of nucleation and incubation,a crystallite will commonly develop into a three-dimensional object with well-deﬁned,low-index crystallographic faces.Figures2(a), (b)and(d)show a few typical growth morphologies of1D nanostructures of ZnO.These structures tend to maximize the areas of the{2¯1¯10}and{01¯10}facets because of the lower energy.The morphology shown inﬁgure2(b)is dominated by the polar surfaces,which can be grown by introducing planar defects parallel to the polar surfaces.Occasional planar defects and twins can be observed parallel to the(0001)plane, but dislocations are hardly seen[27].Figure3.TEM images of the as synthesized ZnO nanoparticles using zinc nitrate hexahydrate in an autoclave at a temperature of120◦C. (Reproduced with permission from[46]©2006Elsevier.)Table1.Partial charge distribution in ZAH derived precursor clusters.(Reproduced with permission for[28]©2006Springer) Precursor clustersδZnδAcZn(Ac)2·2H2O0.471−0.227Zn(Ac)20.469−0.235Zn4O(Ac)60.467−0.245Zn10O4(Ac)120.465−0.254Zn5(OH)8(Ac)2·2H2O0.463−0.269Zn10O4(Ac)12·H2O·7EtOH0.429−0.462EtOZnAc0.411−0.5674.Zinc oxide nanostructures—synthesis methods The synthesis methods of different zinc oxide nanostructures can broadly be classiﬁed as follows:a.Solution phase synthesis:In the solution phase synthesis,the growth process is carried out in a liquid.Normally aqueous solutions are used and the process is then referred to as hydrothermal growth process.Some of the solution phase synthesis processes are1.Zinc Acetate Hydrate(ZAH)derived nano-colloidalsol-gel route[28].2.ZAH in alcoholic solutions with sodium hydroxide(NaOH)or tetra methyl ammonium hydroxide(TMAH)[29–31].3.Template assisted growth[32].4.Spray pyrolysis for growth of thinﬁlms[33,34].5.Electrophoresis[35].b.Gas phase synthesis:Gas phase synthesis uses gaseousenvironment in closed chambers.Normally the synthesis is carried out at high temperatures from500◦C to 1500◦C.Some commonly used gas phase methods are1.Vapour phase transport,which includes vapour solid(VS)and vapour liquid solid(VLS)growth[36–39].2.Physical vapour deposition[40].3.Chemical vapour deposition[41].4.Metal organic chemical vapour deposition(MOCVD)[42].5.Thermal oxidation of pure Zn and condensation[43].6.Microwave assisted thermal decomposition[44].Figure4.Variation in particle size and yield of the ZnO nano powders with growth temperature and pH of the growth solution. Region A:heterogeneous solution;region B:homogeneous solution.(Reproduced with permission from[47]©2000Elsevier.)4.1.ZAH based sol-gel synthesis of ZnO nanostructuresThe sol-gel method has gained a lot of popularity as it offers controlled consolidation,shape modulation and patterning of the nanostructures.Concentrated ethanolic zinc acetate hydrate(ZAH)suspension when reﬂuxed and distilled forms a transparent sol.Small ZnO nanoparticles of dimensions around5nm can be grown under high concentration conditions by addition of hydroxides(e.g.LiOH,NaOH, etc)[28].There are reports of modiﬁcations of the ZAH dehydration or dissolution and subsequent condensation for the growth of ZnO nanostructures[29–31].Table2.Morphologies obtained using different templates. (Reproduced with permission from[48]©1999Elsevier.)Particle properties Additives Morphology Size(nm)Tributylamine Rod-like200–300Triethylamine Rod-like100–300Triethanolamie Spindle-like100–300Diisopropylamine Rod-like200–400Ammonium phosphate Rod-like200–5001,6-Hexadianol Rod-like300–700Triethyldiethylnol Rod-like100–300Isopropylamine Rod or sheet-likeCyclohexylamine Sheet-like300–500n-Butylamine Sheet-like200–400Ammonium chloride Sheet50–200Hexamethylenetetramine Snow-ﬂake like20–50Ethylene glycol Ellipse40–100Ethanolamine Polyhedron50–200 Figure5.Attachment of hexamine to the non polar facets of the zincite crystal allows the growth of the crystal in the(0001) direction.(a)hexagonal ZnO crystal(b)possible attachment of hexamine on to the non polar facets leaving the polar face exposed allowing further crystal growth along the c-direction.(Reproduced with permission from[57]©2006Springer.)Figure6.SEM image of ZnO nanorods grown using zinc nitrate and hexamine after seeding with ZnO nanoparticles.Inset:close up of the rods.(Reproduced with permission from authors[51].) The search for primary clusters to serve as building blocks for various nanostructures has been going on for quite some time.The isolation and identiﬁcation of primary clusters is an area of active research.The synthesis of the primary structures depend on various conditions like initialFigure7.Images of ZnO homocentric bundles obtained in block copolymers systems:(a)SEM image:products in surfactant L64(b)TEM image:products in L64.Inset:diffraction pattern.(c)and(d)SEM images:products in F68.(Reproduced with permission from[73]©2007 Elsevier.)concentration of the salt,the synthesis temperature,heating time as well as nature of the solvent.The ZnO clusters can be members of any of the three different families mentioned below[28]:1.Tetrahedral oxy-acetate Zn4O(Ac)6.2.Ethoxy acetate(EtOZnAc)n.3.Hydroxy-double salt(Zn−HDS)Zn5(OH)8(Ac)2(H2O)2.When Zn(Ac)2is heated in alcohol,the following reaction takes place initially4Zn(Ac)2·2H2O heat−−−−−→Zn4O(Ac)6+7H2O+2HAc.(1) Zn4O(Ac)6is also called basic zinc acetate.The by-products like H2O,acetic acid etc,can be removed by distillation. ZAH forms a larger homologue Zn10O4(Ac)12when it is dehydrated in the presence of acetanhydride and reﬂuxed in EtOH.Continuous reﬂuxing of ZAH sols can result in ZnO nanoparticles[45].Zn4O(Ac)6can be considered as a well designed molecular model of ZnO.Ethoxy acetates(EtOZnAc)n are formed in solutions having Zn10O4(Ac)12clusters.These species are formed gradually with time and after several weeks,large single Table3.Difference reaction for growth of ZnO nanorods. Reproduced with permission from[78]©2007Elsevier.Sample NH4OH(g)Reaction time(h)A1 1.512A2 1.524A3 3.512A4 3.524crystals can be separated.The oxy-acetate clusters most probably generate intermediary zinc acetate monomers as shown by the following reactions:4Zn4O(Ac)6−→Zn10O4(Ac)12+6Zn(Ac)2,(2) Zn4O(Ac)6+Zn10O4(Ac)12−→Zn13O5(Ac)16+Zn(Ac)2.(3) These Zn(Ac)2monomers can lead to formation of zinc ethoxy acetate(EtOZnAc)n crystals and acetic acid.Hydroxy-double salt(Zn-HDS)Zn5(OH)8(Ac)2(H2O)2 is formed by the titration of ZAH solutions with an aqueous solution of sodium hydroxide.Zn-HDS has been detected in precipitates of preheated alcoholic ZAH sols.At high temperatures and after prolonged reﬂuxing,Zn-HDS can be easily transformed into ZnO nanoparticles.Table 4.Morphology and shape of difference ZnO nonostructures at varying pH.(Reproduced with permission from [82]©2008Elsevier.)pH MorphologyShape 9.0Coalescence of Zno CoalescenceBudding ﬂower 9.5Nano-particles ↑10.0Zno nanorodBlossom 10.5Separation sharp rods SeparationChestnut but or echinoid 11.0Separation of thick rods ↓Dense chestnut bur11.5Coalescence of rods Gingko leaves 11.8Archetype of thick rodsCoalescenceDendelionFigure 8.Growth habits of hexagonal prism-and pyramid-like ZnO crystals.(Reproduced with permission from [73]©2007Elsevier.)The occurrence of hydroxy double salts during the growth of ZnO nanoparticles may be due to the following:1.H 2O induced reorganization of the tetrahedral species (primary and secondary)formed during initial nucleation.Hydroxyl ions also play a role.Zn 4O (Ac )6+Zn (Ac )2+9H 2O−→2Zn 5(OH )8(Ac )2(H 2O )2+6HAc .(4)Zn 10O 4(Ac )12+16H 2O−→2Zn 5(OH )8(Ac )2(H 2O )2+8HAc .(5)Zn 10O 4(Ac )12+16H 2O +8OH −−→2Zn 5(OH )8(Ac )2(H 2O )2+8Ac −.(6)2.The continuous liberation of zinc acetate during the growth of the ZnO nanoparticles may be another reason for the growth of the hydroxy doublesalts.Figure 9.SEM images of the array of ZnO obelisk shapednanorods grown on glass substrate.(Reproduced with permission from [75]©2004Elsevier.)4.2.Stability of ZAH derived structuresSpanhel [28]carried out partial charge calculations using the Henry–Livage model.The partial charge values for the ZAH structures are shown in table 1.It can be observed that the tetrahedral oxy-acetate clusters are slightly more stable than the zinc acetate hydrate.Further,the stability of Zn 10O 4(Ac )12precursor is strongly increased in the presence of H 2O and EtOH.Once a certain amount of water is present,there is a spontaneous formation of zinc hydroxy double salts (Zn-HDS).This is because of the higher stability of the Zn-HDS monomer with respect to the naked oxy-acetate clusters.As seen from the table 1,the most stable precursor cluster is the zinc ethoxy-acetate.An important point to note is that Zn 2+ions do not exist as free ions in alcoholic ZAH solutions as a strong chemical bond exists between Zn 2+ions and Ac ligands in all the compounds in table 1.4.3.ZnO nanostructures through hydrothermal growth 4.3.1Nanoparticles.Even though the organometallic synthesis of ZnO nanoparticles in alcoholic medium has received wider acceptance for reasons of faster nucleation and growth as compared to water,still scattered reports of hydrothermal synthesis in aqueous medium are available inFigure10.Illustration of the crystal structure of the obelisk shaped ZnO nanorods.(Reproduced with permission from[75]©2004 Elsevier.)the literature.Baruwati et al[46]have reported the aqueoussynthesis of ZnO nanoparticles using zinc nitrate hexahydrate.Synthesis was carried out in an autoclave at a temperatureof120◦C after adjusting the pH to7.5using ammoniumhydroxide.After washing,the particles were dried at80◦Covernight to obtain the powder form.The as synthesizedparticles are shown in the transmission electron microscope(TEM)images inﬁgure3.Lu et al[47]successfully prepared crystalline ZnOpowder through a hydrothermal process using ammonia asthe base source.With Zn(NO3)2as the source of Zn2+ions, growth was carried out at100◦C,150◦C and200◦C for2hand the effect of growth temperature and pH was studied.Figure4shows the variation of particle size of the ZnOpowder and its yield as functions of growth temperature andpH.With pH<11in region A ofﬁgure4,the zinc hydroxideprecursors are dissolved partially and the ZnO powder isnucleated in a heterogeneous system.On the other hand,in region B with pH 11,all zinc hydroxide precursorsare dissolved and a clear solution is formed so that ZnOpowder is nucleated in a homogeneous solution.Differentnucleation states thus take place in regions A and B withhigher probability of nucleation in the heterogeneous solution.Chen et al[48]synthesized nanoparticles of different morphologies using ZnCl2and NaOH in a hydrothermal growth process using different organic compounds as template agents.A signiﬁcant change in the morphology was observed as the synthesis temperature was increased with the particles changing from rod like to polyhedral.It was reported that the morphology also changed with the addition of different organic templates to the reaction mixture when the temperature was maintained at160◦C.The various morphologies along with the templates used are listed in table2.A very simple procedure to prepare ZnO nanoparticles at a very high pH∼14using tetramethylammonium hydroxide (TMAH)as a precipitating agent was suggested by Musi´c et al[49].Nanoparticles sized from10to20nm were precipitated at room temperature by adding TMAH to an ethanolic solution of zinc acetate dehydrate.Addition of water to the ethanolic solution prior to adding TMAH yielded ZnO snowﬂakes.Vishwanathan and Gupta[50]have shown that supercritical water can also be a good reaction medium for the hydrothermal synthesis of ZnO nanoparticles. Spherical ZnO nanoparticles were synthesized by oxidation of zinc acetate in supercritical water in a continuous tubular reactor.Particle size and morphology can be controlled by varying conditions like temperature,pressure or the reaction atmosphere.Nanoparticles with diameters ranging between 39and320nm were synthesized using this method.The synthesis time has been signiﬁcantly reduced through the use of microwave irradiation and the ZnO nanocrystallites thus formed were observed to be more defective than the ones synthesized over a few hours of hydrolysis[51].Nanoparticles with inherent defects are capable of exhibiting visible light photocatalysis even without doping with transition metals, which is the normally followed method.4.3.2Nanowires and nanorods.Andres-Vergés et al[52]ﬁrst reported the hydrothermal method of growing ZnO nanostructures.However,this could not instil much interest till Vayssieres et al[53]successfully used the method for the controlled fabrication of ZnO nanowires on glass and Si substrates by the thermal decomposition of methenamine and zinc nitrate.To initiate the growth from the substrate,a thin layer of ZnO nanoparticles was grown on the substrate. Methenamine,also known as hexamethylenetetramine(HMT) or hexamine is a highly water soluble,non-ionic tetradentate cyclic tertiary amine.Thermal degradation of HMT releases hydroxyl ions which react with Zn2+ions to form ZnO[54]. This can be summarized in the following equations:(CH2)6N4+6H2O↔6HCHO+4NH3,(7)NH3+H2O↔NH+4+OH−,(8)2OH−+Zn2+→ZnO(s)+H2O.(9) It is a general acceptance that the role of HMT is to supply the hydroxyl ions to drive the precipitation reaction[55].Apart from that,some also opine that HMT acts as a buffer as theFigure11.SEM images of the ZnO nanostructures on Zn foil with condition mentioned in table3:(a)A1(b)A2(c)A3(d)A4. (Reproduced with permission from[78]©2007Elsevier.)rate of its hydrolysis decreases with increasing pH and vice versa[56].Ashfold et al[55]have demonstrated that the rate of decomposition of HMT is independent of the reaction that yields ZnO indicating that HMT does act as a kinetic buffer. In oxide formation,the phase that is thermodynamically less stable will precipitate out faster[56].In the initial growth stage,the pH and the concentration of Zn2+ions is such that the ZnO growth will be through Zn(OH)2.With the gradual increase in the pH and the decrease in the concentration of the Zn ions,Zn(OH)2becomes thermodynamically unstable and the Zn(OH)2formed on the substrate will start dissolving. Further growth of the nanostructures will have to be through direct deposition of ZnO[55].The contribution of HMT in the growth process of ZnO nanowires has also been discussed by Sugunan et al[57] in a totally different approach.It was proposed that HMT, being a long chain polymer and a nonpolar chelating agent, will preferentially attach to the non polar facets of the zincite crystal,thereby cutting off the access of Zn2+ions to them leaving only the polar(001)face for epitaxial growth.HMT therefore acts more like a shape-inducing polymer surfactant rather than as a buffer.Figure5shows the mechanism of attachment of hexamine on the nonpolar facets.There is a lot of literature reporting investigation onthe growth and properties of ZnO nanorods synthesizedusing zinc nitrate and HMT such as the effect of substratesand seed layers on the morphology of nanorods andnanotubes[58–60],growth on different substrates[20]andthe control of aspect ratio through the addition of citrateanions[61].Pal and Santiago[62]have managed to controlthe morphology of ZnO nanostructures by varying the amountof a soft surfactant,ethylenediamine and the pH of thereaction mixture of zinc acetate,sodium hydroxide and thesurfactant.Homogenous growth was observed at a pH of12with inhomogeneity creeping in as the pH decreases.A10%concentrated ethylenediamine gave higher aspect ratiothan5%concentration.Figure6shows scanning electronmicroscope(SEM)images of hydrothermally grown ZnOnanorods using zinc nitrate and hexamine.ZnO nanowires and nanorods have been successfullysynthesized using different surfactants and numerous reportsare available.Tang et al[63]synthesized ZnO nanorodsusing zinc acetylacetonate Zn(acac)2·H2O as a single source precursor and investigated the growth of the rods in thepresence of four different surfactants:polyvinyl alcohol(PV A),polyethylene glycol(PEG),sodium dodecyl sulphateFigure12.SEM images of theﬂower-like ZnO nanostructures at different magniﬁcations.(Reproduced with permission from[79]©2007 Elsevier.)(SDS)and cetyltrimethyl ammonium bromide(CTAB).Theuse of PV A resulted in more regular and defect free rods thanPEG,SDS and CTAB.Li et al[64]has reported the growth oftapered ZnO nanorods with diameter decreasing from400nmat the body to about80nm at the tip from CTAB assistedhydrothermal growth.Zinc acetate dehydrate was used asthe precursor and the pH was adjusted to13using KOH.The use of carbamide CO(NH2)2as a surfactant[65]in a hydrothermal growth with ZnSO4and NaOH yielded highlycrystalline ZnO nanobelts.Chen et al[66]studied the effectof potassium iodide(KI)as a surfactant in the crystallizationof ZnO nanorod clusters from a chemical bath containing zincnitrate hexahydrate Zn(NO3)2·6H2O and hydrazine hydrate N2H4·H2O.They obtained step growth of hexagonal nanorod clusters,and this morphology is attributed to the presence of iodine ions in the growth bath.Stepped columns of ZnO were also observed using CTAB as the surfactant[67].Experiments further showed that the source of Zn ions can also affect the morphology of the end product.Ni et al[67]obtained ZnO nanorods in place of stepped columns simply by changing the source of Zn ions from Zn(Ac)2to ZnCl2and keeping all other conditions same.This may be due to the change in pH of the growth bath.Water soluble amphiphilic block copolymers,PEO-PPO-PEO,due to their unique properties are beingused as templates for the ingenious morphologies ofinorganic materials such as nanoparticles,mesoporousmaterials and hierarchically ordered oxides[68–72].Zhanget al[73]managed to control the shape of bundles of ZnO nanostructures through a macromolecular surfactant(L64 and F68)assisted hydrothermal growth route.The bundles of ZnO nanostructures are shown inﬁgure7.It was deduced that the nanobundle superstructures of ZnO result from a two-step mechanism in aqueous solutions with initial nucleation followed by the growth of the nanorods around these nuclei.Overall size and arm lengths are probably controlled by the growth velocity of ZnO particles and the micelle dimension of PEO–PPO–PEO copolymers.ZnO is a polar crystal,O2−is in hexagonal closest packing,and each Zn2+lies within a tetrahedral group of four oxygen ions[74]. Zn and O atoms are stacked alternatively along the c-axis and the top face(0001)consists of tetrahedral zinc having a terminal OH ligand as shown inﬁgure8.The formation of hexagonal prism and pyramid like ZnO crystals is attributed to the difference in the growth velocities of various crystal facets.The growth velocities under hydrothermal conditions along the different directions are known to follow the pattern V(0001)>V(1011)>V(1010)[73].The relative growth rate of these crystal faces will determine theﬁnal shape and aspect ratio of the ZnO nanostructures.The preferential growth along the(0001)polar direction proceeds unabated and the ZnO nanorods would appear in the end products. Although the chemical reaction is relatively simple,the growth process of ZnO nanobundles is quite complicated.It can be presumed that the faster the growth rate,the quicker the disappearance of the plane.The(0001)plane disappears due to its high growth velocity leading to the pointed shape at the end of the c-axis.As a consequence of the slow growthFigure13.SEM images of ZnO nanoﬂowers synthesized using zinc chloride and ammonia.(Reproduced with permission from[80]©2007Elsevier.)of the(1010)plane,the crystal remains to form the hexagonal prisms,while the(1011)plane corresponds to the formation of the hexagonal pyramid like tips.Wang et al[75]has shown that it is possible to efﬁciently synthesize large two-dimensional arrays of obelisk shaped ZnO nanorods on quartz or glass substrates through a simple hydrothermal deposition method with zinc nitrate, ammonia and ammonium hydroxide as the precursors. The single-crystalline obelisk rods with diameters ranging between300and400nm and lengths of about5µm were grown in Teﬂon vessel at95◦C for30min and the SEM images are shown inﬁgure9.The mechanism for the formation of ZnO crystals using ammonia can be summarized in the following equations [76,77].NH3+H2O⇔NH3·H2O⇔NH+4+HO−,(10)Zn2++NH3→Zn(NH3)42+,(11)Zn(NH3)42++OH−→ZnO.(12)or ZnO may also form from the complex ion Zn(OH)42+as below:Zn2++OH−→Zn(OH)42−,(13)ZnOH42+→ZnO.(14) The complex ions Zn(NH3)42+and Zn(OH)42−formed dueto the mixing of zinc nitrate,ammonia and ammonium hydroxide,dehydrate to initiate heterogeneous nucleation of ZnO on the substrate.The possible formation of the obelisk-shaped single-crystalline rods is attributed to multiple layered structures as explained inﬁgure10.The presence of Zn2+containing salts is not a necessity for the growth of ZnO nanostructures through the hydrothermal growth method.Li et al[78]has successfully grown large scale arrays of ZnO nanorods on zinc foil without the assistance of any template,oxidant or coating of metal oxide layers,simply by dipping the foil into a25%aqueous solution of ammonia(NH4OH)and heating at a temperature 80◦C in a Teﬂon-lined stainless steel autoclave.Four different samples were prepared by varying the concentration of ammonia in a80ml growth bath and the growth duration as shown in table3.The SEM images are shown inﬁgure11.It was observed that the thickness,density and morphology of the ZnO nanorod arrays are affected by the alkalinity of the solution in the growth bath.The sharp tips of the nanorods are probably due to the concentration gradient of Zn2+from the base to the tip.The increase in growth time only led to thicker rods with the lengths remaining almost comparable.With the increase in concentration of ammonia, no growth was observed till12h but a very dense growth of uneven pointed rods was observed when the growth duration was increased to24h.4.3.3Flower-like and cabbage-like nanostructures. Flower-like structures are very typical of ZnO and can be synthesized using simple hydrothermal methods.Wahab et al[79]has reported the growth ofﬂower-like ZnO using hydrothermal method.Theﬂowers,composed of hexagonal ZnO nanorods,were synthesized at a temperature of90◦C using zinc acetate dehydrate and sodium hydroxide in aqueous solutions.Theﬂowers,with nanorod petals as long as2–4µm,could be synthesized in just30min.SEM images of the nanoﬂowers are shown inﬁgure12.All the pointed nanorods emerged from a single centre thereby acquiring the spherical shape.Flower-like ZnO nanostructures with nanosheet petals was synthesized by Shao et al[80]through a hydrothermal route using zinc chloride and ammonia as the reactants.The ﬂowers,averaging in size of about30µm,are composed of sheets of thickness about150–250nm.SEM images (ﬁgure13)reveal numerous well distributed nanostructures formed all over the copper plate substrate.Li et al[81]has reported the growth ofﬂower-like and cabbage-like nanostructures using CTAB as the surfactant in a hydrothermal growth process at temperatures of120,150and 180◦C.They obtainedﬂower-like micro and nanostructures consisting of ZnO nanorods at a temperature of120◦C.。

sol-gel方法。。

薄膜的微观结构，化学成分，表面形貌，以及薄膜的可湿性可通过X -射线衍射，X 射线光电子能谱（XPS ），扫描电镜和水接触角装置进行观察。

薄膜的润湿性和钠 /锌比值关系已详细研究。

通过交替紫外线水性随着薄膜钠/锌比值增加到高达0.08，然后下降。

该机制可能是由于表面纳米结构和钠的掺杂浓度诱导。

通过溶胶凝胶法在石英玻璃和硅衬底上生长钠掺杂的ZnO 薄膜钠掺杂氧化锌薄膜制备方法：乙二醇甲醚和乙醇胺分别被用作溶剂和稳定剂。

二水醋酸锌（Zn(CH3COO)2·2H2O ）在室温下溶解于乙二醇甲醚和乙醇胺混合物中。

乙醇胺和醋酸锌的摩尔比为1:1，醋酸锌浓度为0.5 mol/ L 。

溶解物在60◦ç被搅拌120分钟，在此过程中使用磁力搅拌器来获得清晰，均匀透明溶胶，作为溶胶涂层后维持一天。

石英玻璃和硅被用来作为衬底。

氧化锌薄膜通过一个转速为3000rpm 自旋涂层法自旋30秒获得。

凝胶薄膜在150◦C 温度下被干燥10分钟，此过程重复10次。

这些涂层薄膜在800◦C 的空气中退火处理60分钟。

Electrochemically grown ZnO nanorods for hybrid solar cell applications

Electrochemically grown ZnO nanorods for hybrid solarcell applicationsYakup Hames a ,Zu ¨hal Alpaslan b ,Arif Ko¨semen b ,Sait Eren San b,*,Yusuf Yerli b aDepartment of Electrical-Electronics Engineering,Mustafa Kemal University,31040Hatay,TurkeybDepartment of Physics,Gebze Institute of Technology,41400Gebze,Turkey Received 29July 2009;received in revised form 21October 2009;accepted 27December 2009Available online 10February 2010Communicated by:Associate Editor Dr.Takhir RazykovAbstractA hybrid solar cell is designed and proposed as a feasible and reasonable alternative,according to acquired eﬃciency with the employ-ment of zinc oxide (ZnO)nanorods and ZnO thin ﬁlms at the same time.Both of these ZnO structures were grown electrochemically and poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester;(P3HT:PCBM)was used as an active polymer blend,which was found to be compatible to prepared indium-tin-oxide (ITO)substrate base.This ITO base was introduced with mentioned ZnO structure in such a way that,the most eﬃcient conﬁguration was optimized to be ITO/ZnO ﬁlm/ZnO nanorod/P3HT:PCBM/Ag.Eﬃciency of this opti-mized device is found to be 2.44%.All ZnO works were carried out electrochemically,that is indeed for the ﬁrst time and at relatively lower temperatures.Ó2009Elsevier Ltd.All rights reserved.Keywords:Solar cells;ZnO;Nanorods;Electrochemistry1.IntroductionOrganic materials are promising candidates for photovol-taic technology due to their low cost production and ﬂexible application opportunities,despite the relatively low energy conversion eﬃciency factor,there are various attempts for enhancing the eﬃciency and some of these enhancements were a noteworthy advance such as incorporation of fuller-ene C60as an n-type component into the active polymer (Sariciftci et al.,1992).A promising eﬃciency g =4.8%was acquired in one of these basic organic solar cell struc-tures,ITO/PEDOT:PSS (poly(3,4-ethylenedioxythio-phene)–polystyrenesulfonic acid)/P3HT:PCBM/Al,with surface modiﬁcation of ITO (Yoon and Berger,2008),how-ever instability of PEDOT:PSS is decreasing the device life and it ultimately spoils (Jorgensen et al.,2008).In the scope of this work,conjugate polymers and inor-ganic materials are used altogether in the structure of a hybrid solar cell.ZnO nanorods are employed to raise the durability of the cell and more importantly to construct tidy rods for regulating the movement of charge carriers (Gunes and Sariciftci,2008).Actually ZnO (Beek et al.,2005),CdTe (Kang et al.,2005),TiO 2(Gunes et al.,2006)are some common materials in solar cells.ZnO is of special importance among these alter-natives due to its large band gap semiconductor peculiarity (Ozgur et al.,2005).There are several concrete applications of ZnO such as solar cells (Beek et al.,2006),transistors (HeO et al.,2004),sensors (Liu et al.,2009)and so on.ZnO nanostructures can be grown via diﬀerent techniques.Vapor liquid solid (VLS)(Huang et al.,2001),chemical vapor deposition (CVD)(Wu and Liu,2002),electron beam evaporation (Nakanishi et al.,1999),hydro thermal deposi-tion (Unalan et al.,2008)and electro chemical deposition (ECD)(Gao et al.,2006)and thermal evaporation (Umar0038-092X/$-see front matter Ó2009Elsevier Ltd.All rights reserved.doi:10.1016/j.solener.2009.12.013*Corresponding author.Tel.:+902626051304;fax:+902626538497.E-mail address:erens@.tr (S.E.San)./locate/solenerAvailable online at Solar Energy 84(2010)426–431et al.,2006)are among the famous deposition methods,which were successfully applied for ZnO.Most of these tech-niques are relatively expensive and generally requires high temperature,high sensitivity and application of complicated procedures,except for ECD,which is promising for real life from large scale applicability and feasibility points.Kazuko et al.have already reached 2.7%eﬃciency with polymer:fullerene/ZnO nanorod structure (Takanezawa et al.,2007),however the ZnO nanorods were obtained via Sol-Gel method and annealing was also required at quite high temperatures in their procedure.On the other hand,electrochemical deposition,which we have success-fully applied for ZnO nanorods in our work,enables the control of the dimensions of the nanorods (Guo et al.,2008)and it does not require high temperature annealing,which is also an extra cost factor.The ﬁction of our experimental work contains the pro-posal of a solar cell.The design is simply based on electro-chemically grown ZnO nanorods and these nanorods are actually grown on a ZnO seed layer,which was also elec-trochemically grown on ITO substrates.So,all ZnO prep-arations can be guided in a single process bench.The solar cell eﬃciency was optimized according to the composition of active polymer layer eﬀusing the channels between the nanorods and according to the ZnO thin ﬁlm interlayer.Details of the proposed structure,which was originated throughout a couple of experimental optimization trials,will be given in Experimental Section.2.ExperimentalThe ultimate form of the proposed device is constructed after a couple of attempts and then the most eﬃcient and promising alternative is examined via characterization and optimization procedures.Fig.1reveals the schematic representation of our device.Some of important steps in this design procedure are discussed in this section.2.1.Preparation of ZnO thin ﬁlmFirstly ITO substrates were cleaned with a sequence of chemicals as acetone,isopropinal alcohol,methanol and pure water under the ultrasonic treatment and ITO is set as working electrode in a three electrode system,where ref-erence electrode is Ag/AgCl and graphite is the counter electrode.Solution is distilled water containing 0.1M KCl and 5mM ZnCl 2which was purchased from Aldrich Inc.A constant cathodic current (J =0.012mA/cm 2)is applied for 2500s at room temperature and the result is simply the ZnO thin ﬁlm.Grown thin ﬁlms are annealed at 100°C for 10min.2.2.Preparation of ZnO nanorodsZnO Nanorods’production is subject to a serious optimi-zation of critical conditions,which were determined after a relatively long term and dense trial durations.Our optimized ZnO nanorod production procedure is frankly described in detail as followings;7mM KCl and 6mM ZnCl 2are employed in ultra pure water in three electrode system,sim-ilar to that of the ZnO thin ﬁlm grown,which was already described above.This time,the procedure is applied in a water bath,which is stabilized at 80±1°C.The temperature control is actually a critical parameter in nanorod growing.Also another optimized parameter is the 0.9V cathodic volt-age,with respect to the reference electrode.We were able to grow our ZnO nanorods both on naked ITO and on ZnO thin ﬁlm coated ITO under the same circumstances.200°C annealing is applied for an hour for the produced nanorods.2.3.Device preparationPolymer and PCBM were bought from Aldrich Inc.Chem-ical formulas of the used polymer P3HT and PCBM are given in Fig.2(a)and Fig.2(b)respectively.Polymer blend of P3HT:PCBM was prepared in 1:0.8wt/wt ratio in the chloro-benzene solution and drop-casting method is applied in the coating process.Having coated the active polymer layer,it is subject to 10min annealing at 50°C.The uppermost electrode Ag is deposited via thermal evaporation at 8.16Â10À6mb pressure.Thickness of this Ag layer is $100nm.At last,the device as a whole is annealed at 150°C for 5min.In this point it seems good to state that the prepara-tion and the characterization of the device are performed in ambient conditions.Electrochemical processes were executed with CHI 760C.Current density–voltage (J –V )curves were measured with a Keithley4200semiconductor characterization system,under the illumination of 100mW/cm 2from a 150W Oriel Solar Simulator with AM1.5ﬁlter.Solar Simulator was calibrated by a reference solar cell during the measurements.3.Results and discussion3.1.Preparation of ZnO seed layer and ZnO nanorods based substratesFirstly ZnO nanorods were grown on naked ITO sub-strate as described in Section 2.2.Fig.3(a)depicts thecur-Fig.1.Schematic representation of proposed solarcell.Fig.2.Chemical formulas of the (a)used polymer P3HT and (b)PCBM.Y.Hames et al./Solar Energy 84(2010)426–431427rent versus time of this deposition.If this plot is investi-gated;a sharp decrease is observed in the ﬁrst 1min.Actu-ally this trend implies the increase of the resistance during the nucleation of ZnO on ITO,while the current is rising till 5th min the ZnO grains were formed as previously investigated by Guo et al.(2008).The radius of our rods are around 250–300nm on the ITO surface most probably because there is no guiding ZnO grains,which would con-stitute a preparation seed before the grown of nanorods.The length of these rods are at the order of a micrometers,Fig.4(a).The solar cell based on this infrastructure consti-tutes our ﬁrst solar cell sample.Later on ZnO seed layer was grown on ITO substrate by employing the conditions described in Section 2.1.Fig.3(b)shows the voltage versus time plot of ZnO thin ﬁlm depo-sition and Fig.4(b)depicts the SEM view of the ﬁlm,which is exposed to a 1h annealing at 200°C,once produced.The solar cell based on this infrastructure constitutes our sec-ond design as a solar cell.Lastly as a fruitful combination of these two forms of ZnO,its nanorods are this time grown on the ZnO seed layer thin ﬁlm.The same process was applied for nanorod growth disregarding the ITO morphology of ITO sub-strate.Fig.3(c)demonstrates the current versus time plot.The current value this time drops from 0.1mA to 0.05mA instead of 0.35mA to 0.05mA.One can claim thesmoother grown of the rods when a ZnO seed layer is employed in the substrate.SEM picture Fig.4(c)reveals that the radiuses of the rods as 100–150nm this time,this value is almost half of that of the rods grown without ZnO thin ﬁlm base.The solar cell based on this infrastruc-ture would be our third and last design as a solar cell.3.2.Preparation and characterization of the devices Firstly P3HT:PCBM is prepared as 1:0.8(wt/wt)in a low molarities chlorobenzene solution and this solution is mixed at 70°C for a day.Prepared solution is coated on the sub-strate,which is made up of from ZnO seed layer and ZnO nanorods by drop-casting (DC)method.At this state the prepared item is annealed at 50°C for 10min before the deposition of top electrode in regard to recognized procedure of Takanezawa et al.(2007).Lastly the Ag top electrode is coated by thermal evaporation and a further annealing is applied at 150°C for 5min.In fact,there are some disadvan-tages of DC such as the relatively bad morphology and thicker coating restrictions of the ﬁlms,whereas we have cho-sen this method in regard to its tailored advantage of drain-ing into the prepared nanorod structure.Fig.5demonstrates the cross-section panorama of the prepared device.Actually fully ﬁlled ZnO nanorods,by the polymer blend,are explic-itly shown in thisﬁgure.Fig.3.Current versus time plot of electrochemical deposition for (a)the ZnO nanorods on naked ITO (b)the ZnO thin ﬁlm seed layer (c)the ZnO nanorods grown on ZnO seed layer modiﬁed ITO.428Y.Hames et al./Solar Energy 84(2010)426–431If we look for these three solar cell conﬁgurations,there are important diﬀerences in their responses.Fig.6shows the I –V plots of these cells.Sequentially increasing power conversion eﬃciency was obtained as 1.49%,1.64%and lastly 2.44%from the cells depicted in Table 1.If we consider the ﬁrst cell;prepared without a seed layer but with nanorods (NRs);one can face with a high I sc value around 11.26mA/cm 2while V oc is 0.38V that is a relatively low value.High current value is supposed to be caused from the larger active surface area.Actually this was a part of our ﬁction about why we construct nanorods.Also electrochemical growing is a more controlled technique yielding a better crystalline structure.On the other hand,low V oc value was a handicap and a ZnO thin ﬁlm is introduced in-between nanorods and ITO,in order to cope with this problem.In fact,this idea was previously proposed by Takanezawa et al.(2007).This time we have electrochemically introduced this interlayer thin ﬁlm,which is at the order of 50nm,and low V oc value wasincreased to 0.49V via this interlayer while the I sc is getting a slight decrease to 9.59mA/cm 2.So,the employment of both of these layers,namely the seed layer and Nanorods at the same time is a fruitful design and ITO/ZnO(Seed layer)/ZnO(NRs)/P3HT:PCBM/Ag conﬁguration tried and it yielded an optimized situation with V oc =0.48V and I sc =14.99mA/cm 2with g =2.44%eﬃciency.All measurements are taken under the room conditions just after the cells are produced.“Thermo Oriel Solar Sim-ulator ”is used with AM 1.5conditions and 100mW/cm 2power is attained with standard reference lamp.The used reference standard Si based reference photocell is pur-chased from “Rare System ”and there is no spectral mis-match correction in our ments on the obtained resultsOur device has the inverted geometry,whose top contact is made up of by Ag contact.When the device is illumi-nated by light,excitons are formed in the P3HT.It is then separated as electrons and holes in-between P3HT and PCBM.Electrons are moving ﬁrstly towards ZnO layer and then towards ITO contact,while the holes are going to Ag contact as schematically described in Fig.7.Princi-pally Ag is less reactive with respect to Al,so the stability is better.The thickness of the device is around 1.3l ,and the relatively bigger thickness is simply due to the long ZnO nanorods.One can expect a higher associated serial resistance and consequently lower I sc ,but precise ﬁlling of the regions between ZnO nanorods by P3HT:PCBM blend provided a long surface area between ZnO and the mentioned polymer blend.Therefore,the number of elec-trons to be formed and reaching to ITO gets more,which is causing a relatively higher I sc.Fig.4.SEM picture of the (a)ZnO nanorods grown on naked ITO (b)the ZnO thin ﬁlm seed layer (c)the ZnO nanorods grown on ZnO seed layer modiﬁedITO.Fig.5.Cross-section view of the prepared device.Y.Hames et al./Solar Energy 84(2010)426–431429As we have already stated ﬁrstly,ZNO Nanorods (NR)is grown on naked ITO substrates and the solar cell was constructed and tried with this design,when the V oc value is found to be rather small as 0.38V,and then ZnO thin ﬁlm was deposited between NRs and ITO,so V oc is raisedto 0.48V.In order to be honest,this rise is less than our expectations.One can propose some scenarios for possible reasons of low V oc .We have interpreted our outputs with the recent literature.The introduced seed layer,namely the thin ﬁlm between NRs and ITO is prohibiting the leak-age of polymer blend to ITO,which would cause hole leak-age.Actually this barrier is contributing the increase of current,however these accumulated holes may cause recombination with the electrons from ITO,whereby the V oc could be aﬀected negatively (Unalan et al.,2008).Another possible reason of V oc can be due to the follow-ing explanation.LUMO level of acceptor and HOMO level of donor determines the V oc .There may be some incom-plete splitting of quasi Fermi levels on ZnO,and this may be change HOMO–LUMO levels by mid-gap behav-iors.Actually ZnO surface is quite long in our design and this possibility seems rather realist.Diﬀerent metals could be doped for ZnO for coping with the low V oc value,if this is the real cause.Of course such a doping would take a seri-ous optimization process (Olson et al.,2007).Actually ZnO surface is relatively long in our design and there may be some additional destructive surface eﬀects,this time arising from ZnO–P3HT interface instead of P3HT–PCBM interface,whose constructive contribution is already discussed.This destructive surface eﬀect may be another scenario for low V oc.Fig.6.I –V plots of solar cells based on (a)ZnO nanorods grown on naked ITO (b)the ZnO thin ﬁlm seed layer (c)the ZnO nanorods grown on ZnO seed layer modiﬁed ITO.Table 1Power conversion eﬃciencies of the designed solar cells.Designed solar cellPower conversion eﬃciency g (%)ITO/ZnO(NRs)/P3HT:PCBM/Ag1.49ITO/ZnO(Buﬀer layer)/P3HT:PCBM/Ag1.64ITO/ZnO(Buﬀer layer)/ZnO(NRs)/P3HT:PCBM/Ag2.44Fig.7.Schematic representation of the energy levels in our design.430Y.Hames et al./Solar Energy 84(2010)426–4314.Conclusion and remarks for future studiesA fruitful ZnO based substrate is proposed and optimized throughout the work.The goal of this work is to produce this ZnO staﬀvia merely electrochemical methods and this is promising for low cost production possibilities,which is crit-ical for the realization of organic technology.Channels based structure of ZnO nanorods is shown to be of func-tional characters and we haveﬁlled these channels by P3HT:PCBM blend.Alternative tailored materials could be tried toﬁll the same nanorod structure such as phthalocy-anins or quantum dots.May be better conversion eﬃciencies could be attained via other materials.Also,we have per-formed all preparations and measurements in air conditions, which is apparently a strong disadvantage.One can try the same story in a glove box system.The proposed ZnO concept infrastructure is claimed to be an eﬃcient base for solar cell applications and all ZnO work are carried out electrochem-ically for theﬁrst time in the context of this work. AcknowledgementThis work is partially supported by The Scientiﬁc and Technical Research Council of Turkey;with project refer-ence Number107M270.ReferencesBeek,W.J.E.,Wienk,M.M.,Janssen,R.A.J.,2005.Hybrid polymer solar cells based on zinc oxide.J.Mater.Chem.15,2985–2988.Beek,W.J.E.,Wienk,M.M.,Janssen,R.A.J.,2006.Hybrid solar cells from regioregular polythiophene and ZnO nanoparticles.Adv.Func.Mat.16,1112–1116.Gao,F.,Naik,S.P.,Sasaki,Y.,Okubo,T.,2006.Preparation and optical property of nanosized ZnO electrochemically deposited in mesoporous silicaﬁlms.Thin Solid Films495,68–72.Gunes,S.,Sariciftci,N.S.,2008.Hybrid solar cells.Inorg.Chim.Acta361, 581–588.Gunes,S.,Neugeber,H.,Sariciftci,N.S.,Roither,J.,Kovalenko,M., Pillwein,G.,Heiss,W.,2006.Hybrid solar cells using HgTe nanocrystals and nanoporous TiO2electrodes.Adv.Func.Mat.16, 1095–1099.Guo,M.,Yang,C.Y.,Zhang,M.,Zhang,Y.J.,Ma,T.,Wang,X.D., Wang,X.D.,2008.Eﬀects of preparing conditions on the electrode-position of well-aligned ZnO nanorod arrays.Electrochim.Acta53, 4633–4641.HeO,Y.W.,Tien,L.C.,Kwon,Y.,Norton,D.P.,Pearton,S.J.,Kang,B.S.,Ren, F.,2004.Depletion-mode ZnO nanowireﬁeld-eﬀecttransistor.Appl.Phys.Lett.85,2274.Huang,M.H.,Wu,Y.,Feick,H.,Tran,N.,Weber,E.,Yang,P.,2001.Catalytic growth of zinc oxide nanowires by vapor transport.Adv.Mater.13,113–116.Jorgensen,M.,Norrman,K.,Krebs,F.C.,2008.Stability/degradation of polymer solar cells.Sol.Energy Mater.Sol.Cells92,687–714. Kang,Y.,Park,N.G.,Kim,D.,2005.Hybrid solar cells with vertically aligned CdTe nanorods and a conjugated polymer.Appl.Phys.Lett.86,113101.Liu, C.Y.,Chen, C.F.,Lev,J.P.,2009.Fabrication and CO sensing properties of mesostructured ZnO gas sensors.J.Electrochem.Soc.156,J16–J19.Nakanishi,Y.,Miyake,A.,Kominami,H.,Aouki,T.,Hatanaka,Y., Shimaoka,G.,1999.Preparation of ZnO thinﬁlms for high-resolution ﬁeld emission display by electron beam evaporation.Appl.Surface Sci.142,233–236.Olson, D.C.,Shaheen,S.E.,White,M.S.,Mitchell,W.J.,van Hest, M.F.A.M.,Collins,R.T.,Ginley,D.S.,2007.Band-oﬀset engineering for enhanced open-circuit voltage in polymer-oxide hybrid solar cells.Adv.Func.Mat.17,264–269.Ozgur,U.,Aliov,Y.I.,Liu,C.,Tekke,A.,Reshchikov,M.A.,Cho,S.J., Morkoc,H.,2005.A comprehensive review of ZnO materials and devices.J.Appl.Phys.98,041301.Sariciftci,N.S.,Smilowitz,L.,Heeger,A.J.,Wudl,F.,1992.Photoinduced electron transfer from a conducting polymer to buckminsterfullerene.Science258,1474–1476.Takanezawa,K.,Hirota,K.,Wei,Q.S.,Tajima,K.,Hashimoto,K.,2007.Eﬃcient charge collection with ZnO nanorod array in hybrid photo-voltaic devices.J.Phys.Chem.C111,7218–7223.Umar,A.,Karunagaran,B.,Suh,E.K.,Hahn,Y.B.,2006.Structural optical properties of single-crystalline ZnO nanorods grown on silicon by thermal evaporation.Nanotechnology17,4072–4077.Unalan,H.,Hiralal,P.,Rupesinghe,N.,Dalal,S.,Milne,W.I.,Amara-tunga,G.A.J.,2008.Rapid synthesis of aligned zinc oxide nanowires.Nanotechnology19,255608.Unalan,H.E.,Hiralal,P.,Kuo, D.,Parekh, B.,Amaratunga,G., Chhowalla,M.,2008.Flexible organic photovoltaics from zinc oxide nanowires grown on transparent and conducting single walled carbon nanotube thinﬁlms.J.Matter Chem.18,5909–5912.Wu,J.J.,Liu,S.C.,2002.Low-temperature growth of well-aligned ZnO nanorods by chemical vapor deposition.Adv.Mater.14,215–218. Yoon,W.J.,Berger,P.R.,2008.4.8%Eﬃcient poly(3-hexylthiophene)-fullerene derivative(1:0.8)bulk heterojunction photovoltaic devices with plasma treated AgO x/indium tin oxide anode modiﬁcation.Appl.Phys.Lett.92,013306.Y.Hames et al./Solar Energy84(2010)426–431431。

学校代码11819学校名称东莞理工学院

广东省申请新增学士学位授予专业简况表学科门类门类代码材料科学与工程工学08专业名称专业代码高分子材料与工程080204批准时间2011广东省学位委员会办公室年月日填学校代码：11819 学校名称：东莞理工学院填表说明一、表内各项目要求提供近四年的原始材料备查。

二、本科各专业的专业内涵参见1998 年教育部颁发的《普通高等学校本科专业介绍》。

三、师资结构中的师资指本学科专业在编的具有教师专业技术职务的人员。

专任教师是指具有教师资格、专门从事本专业教学工作的人员。

符合岗位资格是指：主讲教师具有讲师及以上职务或具有硕士及以上学位，通过岗前培训并取得合格证的教师。

四、近4 年生均四项经费包括本科业务费、教学差旅费、体育维持费、教学仪器设备维修费。

各项经费的具体内容为：本专科生业务费：包括专业建设、课程建设、教材建设等费用，进行实验、实习、毕业设计（论文）所需的各种原材料，低值易耗品及加工、运杂费，生产实习费，答辩费，资料讲义印刷费及学生讲义差价支出等。

教学差旅费：教师进行教学调查、资料搜集、教材编审调研等业务活动的市内交通费、误餐费、外地差旅费。

体育维持费：各种低值体育器械和运动服装的购置费、修理费，体育运动会费用，支付场地租金和参加校际以上运动会的教职工运动员的伙食补助费，以及公共体育教研室的业务性报刊、杂志、资料等零星费用。

教学仪器设备维修费：教学仪器设备的经常维护修理费。

五、设计性实验是指给定实验目的、要求和实验条件，由学生自行设计实验方案并加以实现的实验；综合性实验是指实验内容涉及本课程的综合知识或与本课程相关课程知识的实验。

六、本表填写的数据不得超过限报数额，不得随意增加内容。

文字原则上使用小四或五号宋体。

复制（复印）时，必须保持原格式不变，纸张限用A4,双面印刷，装订要整齐。

2－类另U在校生人数当年招生人数今年毕业人数已毕业人数本科19738380专科0000本专业学生情况n教师队伍n-1专业负责人出生年月专业技术职务定职时间是否兼职邱永福最高学位或最后学历（毕业专业、时间、学校、专业）工作单位（至系、所）有代表性的成果1979.7副教授2011.12 博士（纳米科学与技术、2008、香港科技大学）化学与环境工程学院高分子材料与工程在国内外重要学术刊物上发表论文共15篇；出版专者1 部。

锰掺杂氧化锌纳米棒阵列的结构及其磁学性质

522011年第5期第17卷总96期摘要采用水热法制备出垂直于ITO 基底生长的高密度的Mn 掺杂ZnO 纳米棒阵列。

测试阵列的微观结构和磁性。

XPS 证实Mn 已经成功的掺入到纳米棒中。

同时，所有的Mn 掺杂的ZnO 纳米棒在室温都有铁磁性。

而且饱和磁化强度随掺杂浓度的增加先增大后减小。

5%Mn 掺杂的ZnO 纳米棒阵列的饱和磁化强度最大。

铁磁性可能来源于Mn 离子部分取代Zn 离子，Mn 离子之间的铁磁相互作用。

关键词稀磁半导体 Mn 掺杂ZnO 纳米棒阵列水热法Abstract High density Mn-doped ZnO nanorod arrays were vertically grown on ITO sub-strate via hydrothermal reaction. The microstructure and magnetism of the arrays have been examined. X-ray photoemission spectroscopy demonstrates that Mn is successfully doped into the nanorods. Meanwhile, all the Mn-doped ZnO nanorod arrays are ferromagnetic at room temperature. It is also found that the value of the saturation magnetization (M s ) of the ZnO nanorod arrays firstly increases with increasing the Mn concentration and then decreases. The higher Ms value is obtained in the 5 at.% Mn-doped ZnO nanorod arrays. The ferromagnetism comes from the ferromagnetic interaction between the Mn ions, which partly replace Zn ions.Key words DMSs Mn-doped ZnO nanorod arrays Hydrothermal reaction锰掺杂氧化锌纳米棒阵列的结构及其磁学性质Structural and magnetic properties of Mn-doped ZnO nanorod arrays引言稀磁半导体是非磁半导体的部分阳离子被磁性过度金属取代而形成的[1]。

应用超声化学法制备纳米材料

© 2012 NENU IFMC
纳米材料的制备方法：粉碎法纳米粒子制备方法物理法构筑法气相反应法化学法液相反应法其他方法气相分解法气相合成法气-固反应法沉淀法水热法溶胶-凝胶法氧化还原法喷雾法
超声化学法
© 2012 NENU IFMC
声波声波：声源体发生振动引起四周空气振荡，使声以波的形式传播。
空化泡绝热崩溃时产生的高温高压（5500℃和50662～101325 kPa）足以使H2O分子（水分子中O-H键能为500 kJ/mol）分解为· H 和· OH自由基：H2O → · + · H OH
3. 超临界水氧化
© 2012 NENU IFMC
超声化学设备
超声波清洗机
JY92-2D 超声波细胞粉粹机
© 2012 NENU IFMC
制备生物材料
Formation and Characterization of Polyglutamate Core Shell Microspheres
J. AM. CHEM. SOC. 2006, 128, 6540-6541
© 2012 NENU IFMC
总结超声化学法通过超声波产生空穴现象所引发的特殊的物理、化学环境为制备具有特殊性能的新型材料提供了一条重要的途径。目前已经应用超声化学法合成出各种纳米材料：金属合金，氧化物，硫化物，碳材料，生物材料等等。该方法反应时间周期短，对温度、反应体系要求低，并且能制备各种结构的纳米材料，在工业生产中将会有广阔的前景。
© 2012 NENU IFMC
制备碳材料
A Sonochemical Route to Single-Walled Carbon Nanotubes under Ambient Conditions

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Growth of ZnO nanorod arrays on soft substrates by hydrothermal process

【课件】工作总结PPT

超敏感的ZnO镀覆传感器在室温下对甲醛的影响

水热碳化法制备碳纳米材料

种子辅助化学法合成ZnO纳米棒及其表征

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10电沉积种子层化学控制生长氧化锌纳米棒和纳米管

sol-gel方法。。

Growth and photocatalytic properties of one-dimensional ZnO nanostructures prepared by thermal evapo

微生物生长促进剂 英语

氧化锌纳米结构的热蒸发沉积合成及生长机理

Hydrothermal growth of ZnO nanostructures

sol-gel方法。。

Electrochemically grown ZnO nanorods for hybrid solar cell applications

学校代码11819学校名称东莞理工学院

锰掺杂氧化锌纳米棒阵列的结构及其磁学性质

应用超声化学法制备纳米材料

微生物生长促进剂英语