二氧化钛ppt课件

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【课件】改性二氧化钛催化降解有机氟废水PPT

有可能最终确定的最佳条件对废水处理结果不稳定。
六、实验进度安排和经费预算
1、实验进度安排
2011.08——2011.11 查阅文献、设计试验方案、准备试验材料，预作
2011.11——2011.12 开题论证，确定试验方案。 2012.01——2012.04 完成二氧化钛的碘掺杂改性 2012.04——2012.08 完成紫外光催化对1,1,2-三氟
四、研究方法和技术路线
1、碘掺杂二氧化钛的制备
将一定量的碘酸钾加入到 75ml 去离子水中，待溶解完全后往其中加入所需比例的硫酸钛,硫酸钛与碘酸钾的摩尔比分别为 1∶1，2∶1，3∶1，超声混合均匀得到白色浆状液体，用磁力搅拌器搅拌 8 个小时后放入高压水热反应釜中水热 24 小时。
上步产物放入 60℃ 烘箱中烘干过夜。烘干后的产物于空气气氛不同温度（200℃、300℃）下热处理 3h，升温速率为 3℃/min。制得 I/ TiO2光催化剂，分别记为 IT200，IT300。
2、碘掺杂二氧化钛的制备流程图
3、碘掺杂二氧化钛的光催化性能研究
研究以批处理法进行，以自然光为对照。控制条件
为单因素，设定因素如下：3个梯度的催化剂投加量（0.5g/L、1g/L、2g/L），实验设5个温度（20℃、 30℃、40℃、50℃、60℃），6个pH（pH=1、2、3、 4、5、6），5个照射时间（0.5h、1h、1.5h、2h、 2.5h），5个光照强度（12cm、17cm、22cm、 27cm、32cm），有机氟浓度（有机氟体积：水体积 =1:60、1:80、1:100），2个搅拌速度（搅拌、不搅拌），每个处理设2个重复，进行有机氟废水降解实验。步骤如下：
二、国内外研究现状
1、有机氟的降解

二氧化钛

TiO 2nanorod ﬁlms grown on Si wafers by a nanodot-assisted hydrothermal growthDan Tang,Kui Cheng,Wenjian Weng ⁎,Chenlu Song,Piyi Du,Ge Shen,Gaorong HanDepartment of Materials Science and Engineering,State Key Laboratory of Si Materials,Zhejiang University,Hangzhou 31027,Chinaa b s t r a c ta r t i c l e i n f o Article history:Received 12September 2010Received in revised form 6May 2011Accepted 10May 2011Available online 18May 2011Keywords:TiO 2Film Nanorod NanodotsHydrothermal Assisted growthWe report the controlled hydrothermal growth of rutile TiO 2nanorods on Si wafers by using an anatase TiO 2nanodot ﬁlm as an assisted growth layer.The anatase nanodot ﬁlm was prepared on the wafer by phase-separation-induced self-assembly and subsequent heat-treatment at 500°C.The nanodots on the wafer were then subjected to hydrothermal treatment to induce the growth of rutile TiO 2nanorod ﬁlms.The size and dispersion density of the resulting TiO 2nanorods could be varied by adjusting the Ti ion concentration in the growth solution.The TiO 2nanorods were of the rutile phase and grew in the [001]direction.The growth mechanism reveals that the growth of the rutile nanorods was wholly dependent on the existence of rutile TiO 2seeds,which could be formed by the dissolution –reprecipitation of the anatase nanodots during hydrothermal treatment or under the high-temperature conditions of the subsequent heat-treatment of the as-prepared nanodots.In controlling the rutile nanorod growth,the anatase nanodots show more ef ﬁciency than a dense anatase ﬁlm.Preliminary evaluations of the rutile nanorod ﬁlms have demonstrated that the wettability changed from highly hydrophobic to superhydrophilic and that the photocatalytic activity was enhanced with increasing nanorod dispersion density.©2011Elsevier B.V.All rights reserved.1.IntroductionTitania (TiO 2)is attractive for use in various applications by virtue of its photochemical and photovoltaic properties and chemical inertness.TiO 2exists in three crystal structures,of which rutile has advantages over the other two phases (anatase and brookite)in terms of chemical stability,dielectric constant,and ultraviolet (UV)ray absorption rate [1–3].Nanostructured forms of TiO 2,such as nanoparticles,nanospheres,nanorods,and nanosheets,have received considerable attention due to their physical and chemical properties,which differ greatly from those of their bulk counterparts.In recent years,increasing applications of nanostructured TiO 2in different ﬁelds have been explored,for example in photocatalysts,photovol-taics,cosmetics,gas sensors,gate insulator antifogging and self-cleaning coatings for devices,biological areas such as protein folding,micelle and membrane formation,and molecular recognition [4–10].Among the various types of TiO 2nanostructures,there is a particular interest in one-dimensional single-crystalline TiO 2nanostructures such as nanorod or nanowire arrays or ﬁlms because of their lower recombination rate for excited electron –hole pairs,large interface for charge separation,unique optical and electrical properties [11–13],and larger spatial area for the grafting and assembling of functional molecules in dye-sensitized solar cells and biological surface modi ﬁcations.Since the applications of one-dimensional single-crystalline TiO 2nanostructures are strongly dependent on their shapes,size,density,and crystallinity,it is of great signi ﬁcance to explore synthetic techniques by which the nanostructural characteristics can be well de ﬁned and controlled [14].To date,many groups have investigated different paths for the preparation of rutile TiO 2nanorod arrays,for example through the sol –gel template method,hydrothermal treatment,liquid-phase deposition template routes,gas-phase methods,combustion synthesis,metal-organic chemical vapor depo-sition,or anodic oxidation [1,2,15,16].Among these methods,considerable attention has been paid to the hydrothermal method because of its convenience,versatility,high productivity,and low cost.In order to achieve growth of nanorods on substrates such as Si,sapphire,polyethylene terephthalate,and polystyrene by hydrother-mal synthesis,an assisted growth layer is essential.Such a layer on a substrate serves not only to facilitate nucleation but also to strengthen bonding between the substrate and the nanorods [17].Vertical ZnO nanowire arrays on substrates have been grown through the use of textured ZnO and indium-doped tin oxide seeds [18–21],and rutile TiO 2nanorod and nanowire arrays have been grown on transparent conductive ﬁlm coated glass substrates such as ﬂuorine-doped tin oxide and indium tin oxide ﬁlms [22–25].Since the assisted growth layers have been proven to play an indispensable role in the formation of nanorods,the in ﬂuence of the nanostructures of these layers on the growth should be of great value to explore in order to achieve better control of the process.Si wafers are widely used in various optical-electronic devices,and TiO 2nanorods have been applied in photo-sensors/photocatalysts [6–10].Hence,TiO 2nanorods on Si wafersThin Solid Films 519(2011)7644–7649⁎Corresponding author.Tel./fax:+8657187953787.E-mail address:wengwj@ (W.Weng).0040-6090/$–see front matter ©2011Elsevier B.V.All rights reserved.doi:10.1016/j.tsf.2011.05.011Contents lists available at ScienceDirectThin Solid Filmsj o u r n a l h o m e p a g e :w w w.e l s ev i e r.c o m /l o c a t e /ts fcould provide a basis for creating integrated optical-electronic devices.In this work,phase-separation-induced self-assembly[26]was adopted to pre-prepare an anatase TiO2nanodotﬁlm as an assisted growth layer on a Si wafer.A rutile nanorodﬁlm was grown on the wafer by an induced function of the nanodot layer under hydrother-mal treatment.The role of the anatase TiO2nanodotﬁlm as an assisted growth layer was investigated,and the wettabilities and photocata-lytic performances of the grown TiO2nanorods with different densities were measured.A growth mechanism for the TiO2nanorods is proposed.2.Experimental2.1.MaterialsAll chemicals were of analytical reagent grade and were used without further puriﬁcation.All aqueous solutions were prepared using deionized water.2.2.Preparation of the assisted growth layer on Si wafersFor the phase-separation-induced self-assembly to prepare an anatase TiO2nanodotﬁlm on a Si wafer,an ethanol solution with a molar ratio of acetylacetone(AcAc)/tetrabutyl titanate(TBOT)/H2O of 0.3:1:1,containing40mg/L polyvinyl pyrrolidone(PVP),was applied to the wafer by spin-coating at8000rpm for40s[26].The spin-coated wafer was then heated at500°C for2h in a mufﬂe furnace.The resulting nanodotﬁlms were used as assisted growth layers.Through the above procedure,thicker TiO2nanodotﬁlms for X-ray diffraction(XRD)measurement were prepared by repeating the spin-coating process six times.For comparison,a dense anatase TiO2ﬁlm was prepared by using a spinning solution without PVP.Also,to verify the growth mechanism,a TiO2nanodotﬁlm with rutile phase was prepared by heating at800°C.2.3.Hydrothermal growth of TiO2nanorodsTypically,a certain amount of concentrated hydrochloric acid (36.5–38%by weight)was mixed with30mL of deionized water and the requisite amount of TBOT to obtain a total volume of60mL.In this study,the amount of hydrochloric acid was varied by tuning the TBOT concentration from0.02mol/L to0.05mol/L.The mixture of water and hydrochloric acid was stirred under ambient conditions for5min before the addition of the TBOT.To obtain a clear solution,the whole mixture had to be stirred under ambient conditions for a further period of time.Then,the solution was transferred to a50mL Teﬂon-lined stainless steel autoclave,and a piece of TiO2-coated wafer was placed at an angle against the wall of the Teﬂon liner with the coated side facing down.The hydrothermal growth was conducted at160°C for2h in an electric oven.After the growth hadﬁnished,the autoclave was cooled to room temperature in ambient air,and then the wafer was taken out,rinsed extensively with deionized water and ethanol, and allowed to dry in ambient air.An ultrasonically cleaned,uncoated Si wafer was used as a control to study the effect of the assisted growth layer.2.4.Characterizations and measurementsThe crystal structures of the nanodotﬁlm,the denseﬁlm and the nanorodﬁlms were examined by XRD.The XRD patterns were recorded using an X'Pert PRO PANalytical diffractometer using Cu-K R radiation(λ=1.5406Å),scanning from15°to80°at a rate of 2°min−1.The X-ray tube voltage and current were set at40kV and 40mA,respectively.Morphological and lattice structural information was obtained byﬁeld-emission scanning electron microscopy (FESEM,HITACHI,S-4800)with operating voltage of5.0kV,trans-mission electron microscopy(TEM/HRTEM,TECNAI,F-30)with accelerating voltage of300kV,and selected-area electron diffraction (SAED)analysis.To prepare specimens for TEM observation,a piece of wafer with grown nanorods was added to5mL of ethanol in a small glass vial and sonicated for30min.A few drops of the sonicated suspension were then applied to a carbon-coated200mesh copper grid and dried under ambient conditions before imaging.The dispersion density of the nanorods was obtained by counting the amount of nanorods in a given area(25μm2).To ensure the accuracy of the dispersion density,the average value was taken after ﬁve different areas on the substrate had been counted.Wettability was measured by means of an optical contact angle meter(DATAPHYSISE,OCA20).The photocatalytic performance of the TiO2nanorods was determined by the degradation of Rhodamine dye solution.Three wafers(1cm×1cm)bearing nanorods with different densities were immersed in5mL aliquots of aqueous Rhodamine B dye solution with a concentration of10−5mol/L in glass vessels.Prior to irradiation,the vessels were placed in the dark for60min to obtain saturation adsorption of Rhodamine B onto the catalysts.The vessels were then placed in a Solar Box ready for UV-irradiation to induce the photochemical reaction[27,28].The nanorod-bearing wafer/dye solution samples were irradiated in the horizontal direction for 60min,and the distance between the UV lamp(150W xenon arc-lamp with a420nm cut-offﬁlter)and the sample was kept within 15cm.The change of Rhodamine B concentration was measured by means of a double-beam UV/Vis spectrophotometer(TU-1901).3.Results and discussion3.1.The role of the nanodot layerDuring hydrothermal treatment,the TiO2nanorod growth completely depends on whether an assisted growth layer is present on the wafer.Fig.1shows typical FESEM images of hydrothermally treated wafers without any layer(Fig.1a),with a TiO2nanodotﬁlm (Fig.1b),and with a TiO2denseﬁlm,respectively.The images reveal that no growth occurred on the bare wafer,dense tetragonal nanorods with a dispersion density of about83μm−2grew on the nanodotﬁlm, and that the same nanorods grew on the denseﬁlm but with a lower dispersion density of9μm−2.The nanodotﬁlm thus displayed a stronger assisting role for nanorod growth.3.2.Effect of initial Ti concentrationFig.2shows that the density and size of the nanorods could be varied by changing the TBOT concentration in the growth solution. The density of the nanorods increased signiﬁcantly from almost0to 83μm−2for the wafers with the nanodotﬁlm(Fig.2a,b,c,d)and to 10μm−2for the wafers with the denseﬁlm(Fig.2a1,b1,c1,d1)when the TBOT concentration in the growth solution was increased from 0.02to0.05mol/L.Accordingly,the diameter of the nanorods increased from~35nm to~120nm.In addition,the surface of the nanodots(~100nm)became rough(inset in Fig.2a)andﬁne particles of average diameter~27nm from the deposition process appeared on the wafer(inset in Fig.2b).3.3.Microstructural characteristics of the grown TiO2nanorodsFig.3displays the XRD patterns of the coated wafers before and after hydrothermal growth.The nanodots were originally of anatase phase (Fig.3a);however,the diffraction peaks of the grown nanorods changed to match those of the rutile phase(SG,P42/mnm;JCPDS No.65–0191, a=b=0.4517nm and c=0.2940nm)(Fig.3b).Compared to the standard powder diffraction pattern,the remarkably enhanced(101)7645D.Tang et al./Thin Solid Films519(2011)7644–7649and (002)peaks in Fig.3b indicate that the grown nanorods are oriented against the wafer surface.The intensi ﬁcation of the (002)diffraction peak means that the TiO 2nanorods grew in the [001]direction,resulting in an increase in the (101)diffraction peak due to a contact angle between the (101)and (002)planes of approximately 33°[29].The microstructure of the TiO 2nanorods was further characterized by TEM and HRTEM.In some previous studies,TiO 2nanorods have been grown by hydrothermal treatment in the [110],[101],and other directions through the use of seed layers [30–33].In this work,the HRTEM image (Fig.4a)shows that the nanorod was single-crystalline and that the lattice fringes had interplanar spacings of 0.327nm and0.294nm,corresponding to the interplanar distances of the (110)and (001)planes of rutile TiO 2.The [110]axis is perpendicular to the nanorod side walls,indicating that the nanorod grew along the [001]direction,consistent with the XRD data.The sharp SAED pattern of a nanorod examined along the [110]zone axis (Fig.4b)is also indicative of good crystallization.3.4.Growth mechanism of the rutile nanorodsIn this work,anatase TiO 2nanodots were deployed to play an assisting role to grow TiO 2nanorods.However,the resulting TiO2Fig.1.The in ﬂuence of different wafers on the nanorod growth under hydrothermal treatment in solutions containing 0.05mol/L TBOT:(a)uncoated Si wafer;(b)a wafer coated with a TiO 2nanodot ﬁlm;(c)a wafer coated with a dense TiO 2ﬁlm;(a1)hydrothermally treated (a);(b1)hydrothermally treated (b);(c1)hydrothermally treated(c).Fig.2.The in ﬂuence of TBOT concentration in the solution on the nanorod growth:(a,a ′)0.02mol/L;(b,b ′)0.03mol/L;(c,c ′)0.04mol/L;(d,d ′)0.05mol/L;(a –d)wafers coated with TiO 2nanodot ﬁlm;(a1–d1)wafers coated with dense TiO 2ﬁlm.7646 D.Tang et al./Thin Solid Films 519(2011)7644–7649nanorods after hydrothermal treatment were of the rutile phase.The growth mechanism of the TiO 2nanorods is suggested to proceed as follows.Considering the structures,both anatase and rutile phases employ [TiO 6]octahedra as fundamental structural units,but they have different connections.Edge-shared bonding of this unit leads to anatase,while corner-shared bonding results in rutile.In solutions highly acidi ﬁed with HCl,rutile preferentially nucleates due to the growing unit of Ti(IV)oxo species with a small number of OH ligands,which suppresses edge-shared bonding and enhances vertex-shared bonding [26].In addition,anatase TiO 2in highly acidic solution tends to be unstable because its surface is easily protonated and begins to dissolve [34].In this work,when the anatase nanodots on the wafer were immersed in a hydrothermal solution with high acidity,they were partially dissolved.Consequently,the Ti concentration around the nanodots increased,leading to enhanced supersaturation to yield rutile in the hydrothermal solution.Finally,rutile nanoparticles were deposited around the nanodots when a certain amount of the nanodots had been dissolved.This dissolution –reprecipitation process was con ﬁrmed by SEM and TEM images,as shown in Fig.5.TheFig.3.XRD patterns of wafers coated with the assisted growth layer:(a)before hydrothermal treatment;(b)after hydrothermal treatment in the growth solution with 0.05mol/LTBOT.Fig.4.HRTEM image (a)and SAED pattern (b)of a TiO 2nanorod grown in a solution containing 0.04mol/LTBOT.Fig.5.Microstructures of the deposited nanoparticles and rough nanodots in a nanorod ﬁlm grown in a solution containing 0.04mol/L TBOT:(a)cross-sectional view of the ﬁlm;(b)TEM image of nanoparticles,nanodots,and nanorods from the ﬁlm;(c)TEM image and SAED pattern of the rough nanodots;(d)HRTEM image of thenanoparticle.Fig.6.Schematic illustration of the hydrothermal growth process of the rutile nanorods originated from the anatase nanodot ﬁlm.7647D.Tang et al./Thin Solid Films 519(2011)7644–7649smaller nanoparticle of size ~35nm showed lattice fringes (Fig.5d)that matched those of the rutile phase.This particle is believed to be a deposited nanoparticle because its size is as small as the ﬁne ones in the SEM micrograph (Fig.2b).The SAED pattern of the larger particle of diameter ~150nm shows that it consists of rutile and anatase phases.This particle is considered to originate from a nanodot.The former phase comes from the deposition of rutile nanoparticles on the surface of the nanodot,while the latter phase results from the undissolved part.All of the deposited rutile nanoparticles on the surface of the nanodots and wafer can serve as seeds for rutile growth.The orientation attachment mechanism [35]indicates that whether or not a particle will play a seeding role strongly depends on the spontaneous self-organization of the ﬁne grains in the particle to expose a common crystallographic orientation.Here,it is suggested that only the deposited rutile nanoparticles with [001]crystallo-graphic orientation organization are capable of seeding the growth of nanorods.Therefore,higher Ti concentration in the hydrothermal solution results in the deposition of more and larger nanoparticles.As a result,both the number and size of the nanoparticles increase,and the resulting nanorods have high density and large diameter,as shown in Fig.2.Fig.6schematically illustrates the growth mechanism of the rutile nanorods on the wafer with an anatase nanodot ﬁlm as an assisted growth layer.When a dense anatase ﬁlm was used as the assisted growth layer,the hydrothermal growth of TiO 2nanorods was due to the sameformation process.Since the dense ﬁlm has a much smaller speci ﬁc surface area than the nanodot ﬁlm,the assisting activity should be much weaker than that with the latter,resulting in the appearance of only a few nanorods (Figs.1and 2).An additional experiment was carried out in order to verify the above-proposed growth mechanism.As-prepared nanodots on the wafer were heated at 800°C rather than 500°C,and the resulting nanodots were shown to consist of rutile besides anatase (Fig.7a).Under hydrothermal treatment (with 0.02mol/L TBOT),the nanodots containing rutile clearly induced nanorod growth (Fig.7-b2)in comparison with the anatase nanodots (Fig.7-b1).Hence,the growth of rutile nanorods completely depends on the existence of rutile seeds rather than anatase nanodots on the wafers because of the large lattice mismatch between anatase (a =b =0.3785nm)and rutile (a =b =0.4594nm)of 17.6%.This conclusion is in good agreement with the fact that rutile TiO 2nanorods could be grown on ﬂuorine-doped tin oxide (a =b =0.4687nm)with 2%lattice mismatch [23].3.5.Wettability of the TiO 2nanorodsThe wettability of a solid surface depends on both the chemical composition and the geometrical structure [19].The wettability of the nanorods grown on the wafers depends on their dispersion density.Fig.8indicates the wettabilities of nanorods with densities between 9μm −2and 83μm −2.The water contact angle decreases from 119±2.0°to about 0°with increasing density of the nanorods.AtransitionFig.7.The in ﬂuence of heat-treatment temperature of wafers with a TiO 2nanodot ﬁlm on nanorod growth under hydrothermal conditions in a solution containing 0.02mol/L TBOT:(a)XRD patterns of two nanodot-coated wafers heated at 500°C and 800°C;(b)hydrothermally treated wafer heated at 500°C;(c)hydrothermally treated wafer heated at 800°C.Fig.8.The in ﬂuence of different densities of TiO 2nanorod ﬁlms on the water contact angle.7648 D.Tang et al./Thin Solid Films 519(2011)7644–7649from high hydrophobicity to superhydrophilicity could be achieved by controlling the density of the TiO 2nanorods.3.6.Photocatalytic decomposition of Rhodamine B on TiO 2nanorods The photocatalytic activity of TiO 2thin ﬁlms is often coupled with their switchable wettability.In the present work,it was indeed found that an increase in nanorod density led to more extensive degradation of Rhodamine B dye solution (Fig.9).This could be attributed to the larger speci ﬁc surface area for a higher nanorod density.4.ConclusionsAn anatase TiO 2nanodot ﬁlm on a Si wafer has been demonstrated to show a good assisting ability in inducing the hydrothermal growth of nanorods,and represents a good alternative for tailoring the nanorod density and diameter.The resulting TiO 2nanorods are of the rutile phase and grow in the [001]direction.An anatase nanodot ﬁlm showed greater growth-assisting ef ﬁciency than a dense anatase ﬁlm.Here,the growth of rutile nanorods originates from rutile TiO 2seeds formed by the dissolution –reprecipitation of the anatase nanodots during hydro-thermal treatment.The rutile nanorod ﬁlms displayed tunable wetta-bility from highly hydrophobic to superhydrophilic,and enhanced photocatalytic activity with increasing nanorod dispersion density.AcknowledgmentThis work has been ﬁnancially supported by the National Natural Science Foundation (51072178,30870627and 50872122),the Research Fund of the Doctoral Program of Higher Education of China (200703351015),and the Research Fund of Shenzhen Key Laboratory of Functional Polymers.References[1] E.Bae,N.Murakami,T.Ohno,J.Mol.Catal.A:Chem.300(2009)72.[2] E.Bae,T.Ohno,Appl.Catal.,B:Environ.91(2009)634.[3]X.P.Huang,C.X.Pan,J.Cryst.Growth 306(2007)117.[4]W.X.Hou,Q.H.Wang,Langmuir 25(2009)6875.[5]T.X.T.Sayle,D.C.Sayle,ACS Nano 4(2010)879.[6]L.Jiang,Y.J.Zhong,G.C.Li,Mater.Res.Bull.44(2009)999.[7]K.L.Ding,Z.J.Miao,B.J.Hu,G.M.An,Z.Y.Sun,B.X.Han,Z.M.Liu,Langmuir 26(2010)10294.[8] F.Dong,W.R.Zhao,Z.B.Wu,Nanotechnology 19(2008).[9]S.Kim,S.H.Ehrman,Langmuir 23(2007)2497.[10]J.P.Wei,J.F.Yao,X.Y.Zhang,W.Zhu,H.Wang,M.J.Rhodes,Mater.Lett.61(2007)4610.[11]W.Y.Wu,Y.M.Chang,J.M.Ting,Cryst.Growth Des.10(2010)1646.[12]Y.X.Li,M.Guo,M.Zhang,X.D.Wang,Mater.Res.Bull.44(2009)1232.[13]Q.S.Wei,K.Hirota,K.Tajima,K.Hashimoto,Chem.Mater.18(2006)5080.[14]S.W.Yang,L.Gao,Mater.Chem.Phys.99(2006)437.[15]M.N.Tahir,P.Theato,P.Oberle,G.Melnyk,S.Faiss,U.Kolb,A.Janshoff,M.Stepputat,W.Tremel,Langmuir 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二氧化钛的化学合成法 ppt课件

如果将钛醇盐蒸气、水蒸气和有机表面处理剂一起导入反应器，在钛醇盐蒸气气相水解、形成纳米 TiO2 以后，可以对纳米 TiO2 粒子再进行有机表面处理，制备的纳米 TiO2 可用于油漆、高分子材料和催化剂等领域。缺点是原料成本高，不能直接合成金红石型纳米TiO2。
优点
操作温度较低能耗小对材质要求不是很高可以连续化生产
ppt课件
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钛醇盐气相热解法
日本出光兴产株式会社利用钛醇盐气相热解法生产球形非晶型的纳米 TiO2，这种纳米 TiO2 可以用作吸附剂、光催化剂、催化剂载体和化妆品等。
据称，为提高分解反应速率，载气中最好含有水蒸气，分解温度以 250~350°C为合适，钛醇盐蒸气在热分解炉的停留时间为 0.1 ~ 10s，其流速为 10 ~ 1000m/s，体积分数为0.1%~10%;为增加所生成纳米 TiO2 的耐候性，可向热分解炉中同时导入易挥发的金属化合物 (如铝、锆的醇盐) 蒸气，使纳米 TiO2 粉体制备和无机表面处理同时进行。
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钛醇盐气相氧化法
在多孔扩散焰反应器中的氧化 TTIP形成纳米 TiO2 粒子
扩散焰反应器的结构如左图所示。
将钛醇盐蒸气导入反应器与氧气反应，由于饱和蒸气压的原因，反应前驱体一般选用钛酸四异丙醇酯 (TTIP)。
扩散焰反应器由3根同心圆管组成，空气携带着 TTIP蒸气由内管进入反应区，甲烷作为燃料由第2支管子导入火焰区，氧气经最外面的管子也进入火焰区。甲烷和氧气在火焰区燃烧产生的能量用来预热空气和 TTIP，并控制反应区的温度。
当反应温度为700°C，臭氧的摩尔分数为1.4%时，合成的纳米 TiO2 的晶粒尺寸和原始粒径最小，比表面积最大。

4.典型的纳米材料(二)-纳米氧化物

纳米氧化锌的应用
1.橡胶工业中的应用 2.国防工业中的应用 3.纺织工业中的应用 4.涂料防腐中的应用 5.生物医学中的应用
橡胶工业中的应用
纳米氧化锌可以提高橡胶制品的光洁性、耐磨性、机械强度和抗老化性能性能指标。
橡胶工业中的应用
纳米氧化锌粒子较细，对胶料的硫化起步延迟作用较大。随着纳米氧化锌用量增加，其聚集倾向增强，硫化起步的延迟作用逐渐减慢，拉伸强度逐渐增高并趋于稳定，拉断伸长率逐渐降低并趋于稳定。当用量增大到超过5份时，出现填充效应，硫化起步的延迟作用开始变小，综合性能最佳。

4.对有机废水的处理功能
纳米TiO2复合材料对有机废水的处理，效果十分理想。潭湘萍采
用新型载银TiO2的TSA复合催化剂，对印染和精炼废水生化处理后的出水进行深度处理，光照120min后，印染和精炼废水的 CODcr去除率分别为75.3%和83.4%。
方佑龄等人用浸渍法制备了漂浮于水面上的TiO2光催化剂，研究
1.杀菌功能在紫外线作用下，以0.1mg/cm3浓度的超细TiO2可彻底地杀死恶性海拉细胞，而且随着超氧化物歧化酶（SOD）添加量的增多，TiO2光催化杀死癌细胞的效率也提高；用TiO2光催化氧化深度处理自来水，可大大减少水中的细菌数，饮用后无致突变作用，达到安全饮用水的标准。在涂料中添加纳米TiO2可以制造出杀菌、防污、除臭、自洁的抗菌防污涂料，可应用于医院病房、手术室及家庭卫生间等细菌密集、易繁殖的场所，可有效杀死大肠杆菌、黄色葡萄糖菌等有害细菌，防止感染。
生物医学中的应用
• 氧化锌纳米材料促进混合淋巴细胞培养中淋巴细胞的增殖，增强了免疫应答的强度。
纳米材料在免疫调节中

二氧化钛的制备

的纳米TiO2。这种纳米TiO2可以用作吸附剂、光催化剂、催化剂载体和化妆品等等。除了上述各种气相合成法外,气相法还包括低温等离子体化学法、激光化学反应法、金属有机化合物气相沉积法、强光离子束蒸发法、乳液燃烧法等,虽然这些方法制得的粉体纯度高、粒径分布窄、性好,但由于生产成本高,应用价值不大[2]。在上述各种方法中, TiCl4气相氧化法由于经济、环保和生产工艺的柔性而最具竞争力。
气固分离[2]。这种工艺目前还处于实验室小试阶段, 该工艺的关键是要解决喷嘴和反应器的结构设计及
TiO2粒子遇冷壁结疤的问题。这种工艺的优点是自
动化程度高,可以制备出优质的粉体。
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2.3 钛醇盐气ቤተ መጻሕፍቲ ባይዱ水解法
该工艺最早是由美国麻省理工学院开发成功的,可以用来生产单分散的球形纳米二氧化钛,其化学反应式:
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2）加入醋酸的量对凝胶时间的影响：在室温、pH=2～3、m(无水乙醇):m(水):m(钛酸丁酯)=25:5:1 （摩尔比）的条件下，取冰醋酸和钛酸丁酯的摩尔比为0～2，分析冰醋酸的加入量对凝胶时间的影响，见图可知冰醋酸的加入量有0增加至0.25时其凝胶时间相差近10小时，且凝胶时间随冰醋酸加入量的增加而延长。在本次实验中取冰醋酸和钛酸丁酯的摩尔比为0.5。
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3.固相法
固相法合成纳米TiO2是利用固态原料热分解或固-固反应进行的。基础的固相法是钛或钛的氧化物按一定的比例充分混合,研磨后进行煅烧,通过发生固相反应直接制得纳米TiO2粉体,或者是再次粉碎得到纳米TiO2粉体。固相法包括热分解法、固相反应法、火花放电法、高能球磨法等。
Ti(OR)4(g) + 4H2O→Ti(OH)4(s) + 4ROH(g) Ti(OH)4(s)→TiO2·H2O(g) + H2O TiO2·H2O(g)→TiO2+ H2O(g) 由于反应温度不高,所制备的纳米TiO2通常为非晶

纳米TiO2

添加了具有光催化活性的纳米TiO2的环保涂料，已应用于环境空气净化，并扩展到室内的卫生保健，应用领域正在不断扩大。
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2.3.1 光催化环保涂料
纳米TiO2氟碳涂料光照过程产生的羟基与生物大分子（如脂类、蛋白质、酶以及核酸）通过一系列氧化链式反应对生物细胞结构引起广泛的损伤性破坏，攻击有机物的不饱和键或抽取氢原子，使细菌蛋白质变异或脂类分解（多肽链断裂和糖类解聚），将细胞质中的原生质活酶破坏，以此杀灭细菌使之分解，赋予涂料很强的杀菌抑菌功能，对空气中细菌、霉菌、发臭有机物等有净化的作用；有长期的防霉防藻效果，强劲的抗粉尘和抗脏物的粘附能力；疏水性极佳，容易清洗涂层表面的污物。
(5)含汞废水的处理：同六价铬还原相似，无机汞离子从半导体导带到电子而被还原到零价汞。
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2.2.3. 对室内空气中污染物的降解
纳米TiO2光催化技术在清除挥发性有机物上(VOC)具有独到之处，能将许多难于用其他方法降解的污染物最终达到无机化，一般生成二氧化碳和水，以及相应的化合物。
(4)毛纺染整废水处理：把表面涂覆有纳米TiO2膜的玻璃填料填充于玻璃反应器中，毛纺染整废水在反应器内循环进行光催化氧化处理。
(5)印染废水处理
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2.2.2. 降解水中无机污染物
(1)含铬废水的处理：用TiO2掺杂Pb 2+作为吸附剂，利用TiO2薄膜在光催化下使Cr6+转化成Cr3+，去除率为99．5％。
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1.3.3 TiCl4水解法
TiCl4水解法就是以TiCl4为原料，以碱为催化剂，得到 Ti02的水合物，然后经过离心、洗涤、干燥和煅烧即可得到纳米二氧化钛。

二氧化钛生产工艺简介课件

为控制水解速度、水解物的过滤洗涤性能和最终产品的细度及质量指标，需要在水解时加入晶种。晶种的加入方式有两种：自身晶种和外加晶种。
自身晶种是在水解时利用预先加入的水解肽液和水所产生的晶种进行水解工序，不用另外制备晶种。
外加晶种顾名思义是向钛液加入经另外制备的金红石或锐钛型晶种，用
以控制水解速度和钛白产品的最终晶体类型。为此目的的金红石晶种是用偏钛酸-盐酸或纯TiCl4制备，而锐钛型晶种是用偏钛酸、氢氧化钠或向钛液加入水或酸产生的。
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硫酸法生产二氧化钛的典型流程
①酸解：TiO2原料用硫酸酸解； ②沉降，将可溶性硫酸氧钛从固体杂质中分离
出来；
③水解：水解硫酸氧钛以形成不溶水解产物或称偏钛酸；
④煅烧：煅烧除去水分，生成干燥的纯TiO2。 ⑤研磨
⑥包膜：金红石型钛白粉包膜处理。
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1.酸解
经研磨、干燥的钛铁矿（含42%～60%的TiO2）和／或酸溶性钛
钛铁矿中的铁含量越高（TiO2含量越低），所用硫酸的稀释程度就越高。对处理岩矿而言，合适的酸浓度为85%。而处理钛渣，酸中的H2SO4一般为91%～92%。为了获得平缓的反应，不许用比此更浓的硫酸。
之后，钛液被逐渐稀释，首先用酸，然后用水。无论酸的浓度如
何，反应固相物的形态都是疏松的多孔饼，其主要组成是Fe2(SO4)3和
加入酪蛋白、淀粉或其他有机絮凝剂，液体便通过简单的重力分解沉淀在沉降池中。
用旋转耙从沉降池中将固体物质去除。沉降后的钛液通过精滤除掉细小的残余粒子。
整个沉降过程大约8h。
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3.水解
水解工序是硫酸法钛白生产非常关键的一步。这一步将可溶性硫酸氧钛在90℃时水解成不溶于水的水合TiO2沉淀物，或称偏钛酸。

硫酸法生产钛白粉工艺 ppt课件

由于它是白色和浅白色最好的遮盖颜料和消色颜料，因此被广泛地应用于需要着白色或浅白色的涂料、纸张、塑料、油墨、橡胶等领域。随着世界经济的发展和人类科技的进步，人们对钛白粉的认识将越来越深，钛白粉的应用领域将越来越广，钛白粉的市场需求将越来越大，钛白粉有着及其宽广的发展和应用前景。
硫酸法生产钛白粉工艺
钛白粉的性质及用途
硫酸法生产钛白粉工艺
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钛白粉的化学名称为二氧化钛，英文名称为titanium dioxide或titania。商用名称为钛白粉，分子式为TiO2，相对分子质量为79.9。
基于钛白粉具有稳定的物理、化学性质，优良的光学、电学性质以及优异的颜料性能，因此其用途十分广泛，涂料、塑料、造纸、化纤、油墨、橡胶、电子工业、化妆品、电焊条、搪瓷、陶瓷和冶金等都要用到钛白粉。特别是颜料钛白粉，因其具有其他白色颜料无可比拟的多种优异性能，以至于其面世后，很快就取代了传统的铅白、锌白、锌钡白等白色颜料，成为白色颜料之王。
硫酸法生产钛白粉工艺
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2.沉清/沉降
硫酸法生产钛白粉工艺
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冷却酸解液、固体惰性物质和未反应的原料残余物溶液从酸解罐的底部全部排放到宽底的地位沉淀池/沉降池中。
此处是将由钛矿杂质形成的可溶性残余物去掉。这些残余物可能包括硅石、锆石/硫酸石、白钛石和/或金红石。加入酪蛋白、淀粉或其他有机絮凝剂，液体便通过简单的重力分解沉淀在沉降池中。可溶性残余物的沉降可以在此阶段辅以硫化锑（SbS3）沉淀的形式进行。为此，需在酸解阶段将氧化锑加入到最初的原料中，沉降时加入硫化钠以沉淀SbS3。
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1.酸解
经研磨、干燥的钛铁矿（含42%～60%的TiO2）和／或酸溶性钛渣（TiO2含量72%～78%）一般在铅衬反应器中用浓硫酸在150～180℃的温度下酸解。为便于酸解，原料通常要磨到200目左右。需要指出的是，白钛石、人造金红石和金红石不溶解于硫酸，因此不能用硫酸法钛白的生产方法。

二氧化钛

白色粉末
白色粉末
晶型
金红石含量% 粒径(nm) 干燥减量% 灼烧减量% 表面特性 PH 比表面积（m2/g) 重金属（以Pb计）%
金红石型
99 20-50 1 ####### 亲水性或亲油性 6.5-8.5 80-200 0.0015
锐钛型
-15-50 1 10 亲水性或亲油性 6.5-8.5 80-200 0.0015
1.1.等离子体法等离子体法是通过激活载气携带的原料形成等离子体，再加热反应生成超微粒子的方法。以TiCl4为原料，氢气为载气，氧气为反应气体，应用频率为2450MHz的微波诱导可合成有机膜包裹的TiO2[4]。1992年，日本东北大学采用等离子体（ICP）喷雾热解法以Ti的氯化物为原料制得了Ti的氧化物的超微粉。等离子体喷雾法是利用等离子体喷枪能产生50000K高温的特点，将这种喷枪的喷出物急骤冷却而生成纳米级的超微粒子 1.2.水解法水解法主要是利用金属盐在酸性溶液中强迫水解产生均匀分散的纳米粒子。已有报道，在硫酸根离子和磷酸根离子存在条件下，用20min到两周左右缓慢地加水分解氯化钛溶液时可得到金红石型纳米TiO2[5]。水解法又可以分为很多种，以下是几种常见的水解法： 1.2.1.TiCl4氢氧火焰水解法该法是将TiCl4气体导入氢氧火焰中（700~1000℃）进行水解，其化学反应式为： TiCl4（g）+2H2（g）+O2（g）→TiO2（s）+4HCl（g）这种工艺制备的粉体一般是锐钛型和金红石型的混合型产品，纯度高、粒径小、表面积大、分散性好、团聚程度较小，但成本较高[4]。
砷（As) W% 铅（Pb) W% 汞（Hg) W%
0.0008 0.0005 0.0001

二氧化钛PPT课件

LOGO N/Gd共掺杂TiO2纳米管阵列太阳能电池薄膜材料及电池光电性能研究
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研究背景及现状
2
研究内容
3
研究方案
4
可行性分析及创新点
2
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1.1 研究背景
❖ 随着现代科技的发展、人口的增加，整个世界面临着能源危机和环境污染两大问题。而太阳能是一种无污染并且取之不尽的能源，具有独特的优势和巨大的开发利用潜力，充分利用太阳能有利于保持人和自然的和谐发展。
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XRD
TEM
BET 3.4 材料的表征
SEM
UV-Vis
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3.5 光电性能研究
（1）交流阻抗测试在0.1mol/L Na2SO4溶液中，采用三电极体系，N-Gd-TiO2/Al为工作电极，对电极为 Pt电极，参比电极为饱和甘汞电极(SCE)，交流阻抗测量频率范围为10-2至105Hz，交流电压幅值为5mV，改变偏压或光照条件进行交流阻抗测试。
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目前制备有序阵列TiO2纳米管的方法有：阳极氧化法、模板合成法、水热合成法等。而模板法中最常用的模板主要是含有孔洞无序分布的高分子模板和有序孔洞阵列氧化铝模板（PAA）。而多孔氧化铝模板由于具有耐高温，绝缘性好，孔径孔深大小可控和稳定的化学惰性等特点，已经成为纳米材料制备的研究热点。
（1）一次阳极氧化（2）将氧化的铝片在 H3PO4（6wt%）和H2CrO4（1.8wt%）混合液(除膜液)中，在30℃下浸泡10h或者在60℃下浸泡6h （3）采用与一次阳极氧化相同的条件进行二次阳极氧化。
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后处理过程
二次阳极氧化之后的后处理过程主要包括：去除铝层、去除阻挡层及扩孔。