微波辅助的多元醇法合成CoNi纳米材料_英文_

合集下载

ceo2 纳米粒子的合成

ceo2 纳米粒子的合成英文回答：Synthesis of CEO2 Nanoparticles.Cerium oxide nanoparticles (CEO2) are versatile materials with a wide range of applications, including in catalysis, sensors, and biomedicine. Their unique properties, such as their high oxygen storage capacity, redox activity, and low toxicity, make them particularly attractive for various applications.There are several methods for synthesizing CEO2 nanoparticles, including chemical precipitation, sol-gel, hydrothermal, and combustion synthesis. Each method has its own advantages and disadvantages, and the choice of method depends on the desired properties of the nanoparticles.Chemical Precipitation.Chemical precipitation is a simple and cost-effective method for synthesizing CEO2 nanoparticles. In this method, a cerium salt, such as cerium nitrate or cerium chloride,is dissolved in water and then precipitated by adding a base, such as sodium hydroxide or ammonium hydroxide. The precipitate is then washed and dried to obtain the CEO2 nanoparticles.The chemical precipitation method is versatile and allows for the control of the size, shape, andcrystallinity of the nanoparticles. However, this methodcan be sensitive to the reaction conditions, and it can be difficult to obtain nanoparticles with uniform properties.Sol-Gel.The sol-gel method involves the hydrolysis and condensation of a cerium precursor, such as cerium alkoxide, in a solvent. The resulting sol-gel is then heated to form the CEO2 nanoparticles.The sol-gel method offers good control over the sizeand shape of the nanoparticles. However, this method can be time-consuming and can require specialized equipment.Hydrothermal.Hydrothermal synthesis is a method for synthesizing CEO2 nanoparticles in a closed vessel under high temperature and pressure. In this method, a cerium precursor is dissolved in water and then heated in a sealed vessel. The high temperature and pressure promote the formation of CEO2 nanoparticles.The hydrothermal method is a versatile method that allows for the control of the size, shape, andcrystallinity of the nanoparticles. However, this method can be expensive and can require specialized equipment.Combustion Synthesis.Combustion synthesis is a method for synthesizing CEO2 nanoparticles by rapidly heating a mixture of ceriumnitrate and a fuel, such as glycine or urea. The rapidheating causes the fuel to combust, which provides the energy for the formation of CEO2 nanoparticles.Combustion synthesis is a simple and cost-effective method. However, this method can be difficult to control, and it can be difficult to obtain nanoparticles withuniform properties.中文回答：CEO2 纳米粒子的合成。

微波辅助离子液体合成球形纳米团簇2010年1月

/Langmuir©2010American Chemical SocietyIonic Liquid-Based Route to Spherical NaYF4Nanoclusters with the Assistance of Microwave Radiation and Their Multicolor UpconversionLuminescenceCheng Chen,†,‡Ling-Dong Sun,†Zhen-Xing Li,†Le-Le Li,†Jun Zhang,*,‡Ya-Wen Zhang,†and Chun-Hua Yan*,††Beijing National Laboratory for Molecular Sciences,State Key Lab of Rare Earth Materials Chemistry and Applications,PKU-HKU Joint Lab in Rare Earth Materials and Bioinorganic Chemistry,Peking University, Beijing100871,P.R.China,and‡College of Chemistry and Chemical Engineering,Inner Mongolia University,Hohhot010021,P.R.ChinaReceived December2,2009.Revised Manuscript Received January3,2010An ionic liquid(IL)(1-butyl-3-methylimidazolium tetrafluoroborate)-based route was introduced into the synthesis of novel spherical NaYF4nanoclusters with the assistance of a microwave-accelerated reaction system.X-ray diffraction (XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution TEM (HRTEM),selected area electron diffraction(SAED),energy-dispersive X-ray spectroscopy(EDS)and upconversion (UC)luminescence spectroscopy were used to characterize the obtained products.Interestingly,these spherical NaYF4 nanoclusters with diameters ranging from200to430nm are formed by the self-assembly of small nanoparticles.The diameters of the nanoclusters could be easily tuned just by changing the amounts of the precursors.By conducting the control experiments with different ILs or precursors,it is proven that the ILs have played key roles,such as the solvents for the reaction,the absorbents of microwave irradiation,and the major fluorine sources for the formation of the NaYF4 nanocrystals.The UC luminescence properties of the Ln3þcodoped NaYF4were measured,and the results indicate that the nanoclusters obtained in BmimBF4exhibit excellent UC properties.Since this IL-based and microwave-accelerated procedure is efficient and environmentally benign,we believe that this method may have some potential applications in the synthesis of other nanomaterials.1.IntroductionIonic liquids(ILs)have recently attracted much attention since they have a variety of potential applications in organic synthesis, electrochemistry,catalysis,chemical separation,and so on.1ILs can be used as green solvents to replace conventional organic solvents in many chemical processes because of their unique properties,such as their negligible vapor pressure,good thermal and chemical stability,extremely high ionic conductivity,wide electrochemical windows,and so on.2,3In recent years,ILs have emerged as one of the most promising categories of medium for the fabrication of nanomaterials with various morphologies,since ILs possess tunable properties so that they can easily interact with various surfaces and chemical reaction environments.4-6 Smarsly et al.designed a low-temperature route to synthesize rutile nanorods just by the stabilization of an amorphous phase,which then converted to rutile by a simple extraction of the stabilizer (IL).7Chen et al.demonstrated a novel route for the prepara-tion of IL-stabilized ZnO nanocrystals with remarkably high photoluminescence quantum yields.8Moreover,because of their high polarity,ILs are also considered to be excellent microwave absorbents.9Microwave dielectric heating has aroused many interests in recent years because there are many advantages compared to conventional heating for chemical reactions,such as higher heating rate,uniform heating without thermal gradients, selective heating properties,and higher yields in shorter reaction time.10,11Because of these special properties,microwave irradia-tion is becoming an important pathway for the preparation of nanomaterials.It not only benefits the spontaneous nucleation of inorganic materials,12-14but also enables reactions to be per-formed at higher temperatures,which results from the super-heating phenomenon of the solvents caused by the microwave dielectric heating.15,16The exploration of the combination be-tween ILs and microwave radiation has just begun,which would facilitate the fabrication of novel nanomaterials with designed structures and functions.17-19*Corresponding author.Fax:þ86-10-6275-4179;e-mail:yan@(C.-H.Y.).Fax:þ86-471-499-2278;e-mail:cejzhang@(J.Z.).(1)Parvulescu,V.I.;Hardacre,C.Chem.Rev.2007,107,2615.(2)Antonietti,M.;Kuang,D.B.;Smarsly,B.;Zhou,Y.Angew.Chem.,Int.Ed. 2004,43,4988.(3)Gao,H.X.;Li,J.C.;Han,B.X.;Chen,W.N.;Zhang,J.L.;Zhang,R.;Yan,D.D.Phys.Chem.Chem.Phys.2004,6,2914.(4)Lodge,T.P.Science2008,321,50.(5)Kim,T.Y.;Kim,W.J.;Hong,S.H.;Kim,J.E.;Suh,K.S.Angew.Chem., Int.Ed.2009,48,3806.(6)Zhou,Y.;Antonietti,M.Adv.Mater.2003,15,1452.(7)Kaper,H.;Endres,F.;Djerdj,I.;Antonietti,M.;Smarsly,B.M.;Maier,J.; Hu,Y.S.Small2007,3,1753.(8)Liu,D.P.;Li,G.D.;Su,Y.;Chen,J.S.Angew.Chem.,Int.Ed.2006,45, 7370.(9)Ding,K.L.;Miao,Z.J.;Liu,Z.M.;Zhang,Z.F.;Han,B.X.;An,G.M.; Miao,S.D.;Xie,Y.J.Am.Chem.Soc.2007,129,6362.(10)Gabriel,C.;Gabriel,S.;Grant,E.H.;Halstead,B.S.J.;Mingos,D.M.P. Chem.Soc.Rev.1998,27,213.(11)Hu,X.L.;Yu,J.C.Adv.Funct.Mater.2008,18,880.(12)Gerbec,J.A.;Magana,D.;Washington,A.;Strouse,G.F.J.Am.Chem. Soc.2005,127,15791.(13)Kim,S.H.;Lee,S.Y.;Yi,G.R.;Pine,D.J.;Yang,S.M.J.Am.Chem.Soc. 2006,128,10897.(14)Hu,X.L.;Gong,J.M.;Zhang,L.Z.;Yu,J.C.Adv.Mater.2008,20,4845.(15)Baghurst,D.R.;Mingos,mun.1992,9, 674.(16)Saillard,R.;Poux,M.;Berlan,J.Tetrahedron1995,51,4033.(17)Yang,L.X.;Zhu,Y.J.;Wang,W.W.;Tong,H.;Ruan,M.L.J.Phys. Chem.B2006,110,6609.(18)Buhler,G.;Feldmann,C.Angew.Chem.,Int.Ed.2006,45,4864.(19)Lovingood,D.D.;Strouse,G.F.Nano.Lett.2008,8,3394.Article Chen et al.Recent decades have witnessed an explosion in research devoted to preparing upconversion(UC)nanocrystals because of their potential applications in solid-state lasers,optical sto-rage,flat-panel displays,optical fiber-based telecommunica-tions,low-intensity IR imaging,and so on.20,21As an impor-tant category of rare earth fluoride compounds,AREF4(A= alkali;RE=rare earth)is regarded as an excellent host matrix for UC phosphors.22,23Great efforts have been devoted to the synthesis of shape-controllable NaYF4nanocrystals via different routes and the study of their optical properties.24-26Zhao et al. reported the synthesis of NaYF4nanotubes via an in situ ion exchange procedure from the corresponding hydroxides.27van Veggel’s group developed an efficient route to prepare a UC nanoparticle-polymer composite.28A core/shell structure of NaYF4/silica was prepared by Zhang’s group,and multi-color UC fluorescence properties of the nanoparticles were measured.29,30Recently,IL was also applied to synthesize hexagonal-phase NaYF4UC nanophosphors through an ionothermal method.31However,the unique properties of ILs, such as their high polarity and the resulting excellent microwave absorbing ability,have not been reflected and emphasized. Additionally,the effects of different ILs on the formation process of the final nanostructures have not been investigated.In this work,we have introduced a microwave-accelerated reaction system into the synthesis of novel spherical NaYF4 nanoclusters in1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4),with which the reactions could be completed in a significantly short time and highly crystallized products could be obtained.Interestingly,these NaYF4nanoclusters are formed by the self-assembly of small nanoparticles and exhibit excellent UC luminescent property.By conducting control experiments,it is proven that ILs play key roles in the formation of the final nanostructure,since they act not only as the solvents and micro-wave absorbents in the synthetic process,but also as the major fluorine sources for the preparation of NaYF4nanocrystals.2.Experimental Section2.1.Materials.Trifluoroacetic acid(99%,Acros),Na-(CF3COO)(>97%,Acros),Na(CH3COO)(99.0%,Beijing Che-mical Plant),1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4,99%,Alpha),1-butyl-3-methylimidazolium hexa-fluorophosphate(BmimPF6,98%,Alpha),and1-butyl-3-methyl-imidazolium bromide(BmimBr,99%,Alpha)were used as received.RE(CF3COO)3(RE=Y,Yb,Er,Tm)and Y(CH3COO)3 were prepared from the corresponding lanthanide oxides follow-ing the literature method.322.2.Synthesis of NaYF4with Trifluoroacetate Salts in BmimBF4.For a typical synthesis,0.5mmol Na(CF3COO)and0.5mmol Y(CF3COO)3were taken as the precursors and added into5mL IL(BmimBF4)followed by vigorously magnetic stirring at room temperature for2h to obtain a transparent solution,which was then heated to200°C by microwave irradiation and maintained for5min.The temperature ramping process was accomplished by two steps(20°C/min from room temperature to100°C and then10°C/min from100to200°C)in a CEM microwave-accelerated system at400W.After the microwave reaction was completed,the temperature of the system was reduced to room temperature.Then after washing and centrifugation several times,white precipitates were collected and dried at65°C.2.3.Synthesis of NaYF4with Acetate Salts in BmimBF4. The synthetic procedure was the same as that used to synthesize cubic NaYF4in BmimBF4,except that0.5mmol Na(CH3COO) and0.5mmol Y(CH3COO)3were taken as the precursors instead of the trifluoroacetate salts.2.4.Reaction of Trifluoroacetate Salts in BmimBr.The synthetic procedure was the same as that used to synthesize cubic NaYF4by the reaction of Na(CF3COO)and Y(CF3COO)3, except that BmimBr was used as the solvent instead of BmimBF4.2.5.Synthesis of NaYF4with Trifluoroacetate Salts in BmimPF6.The synthetic procedure was the same as that used to synthesize cubic NaYF4by the reaction of Na(CF3COO)and Y(CF3COO)3,except that BmimPF6was used as the solvent instead of BmimBF4.2.6.Synthesis of NaYF4:Yb,Er and NaYF4:Yb,Tm with Trifluoroacetate Salts in BmimBF4.The synthetic procedure was the same as that used to synthesize cubic NaYF4in BmimBF4, except that0.5mmol Na(CF3COO)and stoichiometric amounts of Y(CF3COO)3,Yb(CF3COO)3,Er(CF3COO)3/Tm(CF3COO)3 were taken as the precursors.2.7.Synthesis of NaYF4:Yb,Er and NaYF4:Yb,Tm with Trifluoroacetate Salts in BmimPF6.The synthetic procedure was the same as that used to synthesize cubic NaYF4in BmimPF6, except that0.5mmol Na(CF3COO)and stoichiometric amounts of Y(CF3COO)3,Yb(CF3COO)3,Er(CF3COO)3/Tm(CF3COO)3 were taken as the precursors.2.8.Characterization.Powder X-ray diffraction(XRD) patterns of the dried powders were recorded on a Rigaku D/ MAX-2000diffractometer(Japan)with Cu K R radiation(λ= 1.5406A).Scanning electron microscopy(SEM)observations were carried out with DB-235focused ion beam(FIB)system operated at an acceleration voltage of15kV.Transmission electronic microscopy(TEM),and selected area electron diffrac-tion(SAED)were performed with a JEOL-2100transmission electron microscope(Japan)operated at200kV.High-resolution TEM(HRTEM)characterization and energy-dispersive X-ray spectroscopy(EDS)were taken on a JEOL-2100F transmission electron microscope(Japan)equipped with an EDS detector.The UC luminescence spectra were recorded on a Hitachi F-4500 fluorescence spectrophotometer equipped with an external tun-able2W980nm laser diode(P max=500mW at1000mA).3.Results and DiscussionThe combination of ILs and microwave dielectric heating could provide us with a facile and green route to fabricate nanomater-ials.The XRD pattern of the product synthesized with trifluor-oacetate salts(Na(CF3COO)and Y(CF3COO)3)in BmimBF4is shown in Figure1a.All the peaks can be well indexed as a cubic phase of NaYF4(JCPDS card No.39-0724).The well-resolved four peaks between20°and60°in2θvalue could be assigned to (111),(200),(220),and(311)planes of cubic NaYF4nanocrystals. The SEM image(Figure2a)indicates that NaYF4nanospheres with diameters ranging from200to430nm could be obtained. The TEM image(Figure2b)shows that these spherical nanoclus-ters have rough surfaces,and they are formed by the self-assembly of small nanoparticles.The inset of Figure2b is the SAED pattern(20)Zhang,F.;Wan,Y.;Yu,T.;Zhang,F.Q.;Shi,Y.F.;Xie,S.H.;Li,Y.G.; Xu,L.;Tu,B.;Zhao,D.Y.Angew.Chem.,Int.Ed.2007,46,7976.(21)Sivakumar,S.;van Veggel,F.C.J.M.;May,P.S.J.Am.Chem.Soc.2007, 129,620.(22)Boyer,J.C.;Cuccia,L.A.;Capobianco,J.A.Nano.Lett.2007,7,847.(23)Li,C.X.;Yang,J.;Yang,P.P.;Zhang,X.M.;Lian,H.Z.;Lin,J.Cryst. Growth Des.2008,8,923.(24)Mai,H.X.;Zhang,Y.W.;Si,R.;Yan,Z.G.;Sun,L.D.;You,L.P.;Yan,C.H.J.Am.Chem.Soc.2007,129,6362.(25)Wang,L.Y.;Li,Y.D.Chem.Mater.2007,19,727.(26)Wang,H.Q.;Nann,T.ACS Nano2009,3,3804.(27)Zhang,F.;Zhao,D.Y.ACS Nano2009,3,159.(28)Boyer,J.C.;Johnson,N.J.J.;van Veggel,F.C.J.M.Chem.Mater.2009, 21,2010.(29)Li,Z.Q.;Zhang,Y.;Jiang,S.Adv.Mater.2008,20,4765.(30)Qian,H.S.;Guo,H.C.;Ho,P.C.L.;Mahendran,R.;Zhang,Y.Small 2009,5,2285.(31)Liu,X.M.;Zhao,J.W.;Sun,Y.J.;Song,K.;Yu,Y.;Du,C.;Kong,X.G.; Zhang,mun.2009,43,6628.(32)Roberts,J.E.J.Am.Chem.Soc.1961,83,1087.Chen et al.Articletaken on a single sphere.The discontinuous rings again reveal that the cluster is formed by the aggregation of many small nanopar-ticles.Observation from the HRTEM image (Figure 2c)reveals that the size of the small nanoparticles in these nanoclusters is about 10to 15nm.Moreover,the nanoparticles are single crystals with an interplanar spacing of 0.31nm corresponding to the (111)facets of cubic NaYF 4,which confirms that the nanoparticles are highly crystallized.Scheme 1illustrates the formation process of the spherical NaYF 4nanoclusters.Since the ILs with high polarity have strong microwave absorbing ability,the whole reaction system could reach a high temperature rapidly under microwave irradiation,which results in spontaneous nucleation.9Followed by the rapid growth of these nuclei,large quantities of NaYF 4nanocrystals are formed within an extremely short time.Therefore,the size of the as-synthesized nanoparticles is very small.Because of their high surface energy,the freshly formed small nanoparticles tend to aggregate rapidly into spherical nanoclusters.14Furthermore,the size of the spherical NaYF 4nanoclusters could be tuned by changing the amounts of the trifluoroacetate precursors.As shown in Table 1,samples 1-3were prepared bychanging the amounts of the trifluoroacetate salts from 0.5to 0.1mmol.It could be observed from the TEM images in Figure 3a,c,e that the size of the NaYF 4nanoclusters decreases with the decrease of the precursors’amounts.By measuring 200nanoclusters for each sample,we could get the size distribu-tions of the nanoclusters (Figure 3b,d,f),and the average sizes of these three samples are 302,163,and 79nm,respectively.This size tunability could be resulted from the differences in crystal nuclei caused by varying additions of the precursors.33Because higher concentration of trifluoroacetate salts could accelerate the decom-position of Na(CF 3COO)and Y(CF 3COO)3,more nuclei would form in the solution,which leads to the formation of larger NaYF 4nanoclusters.The factors governing the formation of the spherical NaYF 4nanoclusters were studied,and it was found that the IL had played key roles in the self-assembly process of the final nano-structure.As is known,the existence of sodium,yttrium,and fluorine sources is indispensable for the formation of NaYF 4nanocrystals.In this method,both the precursors (trifluoroace-tate salts)and the solvent (BmimBF 4)might serve as the supplier of the fluoride ions.In order to investigate where the fluoride ions came from and the role that IL played on the synthetic procedure of NaYF 4,control experiments were carried out by changing the inorganic precursors or the ILs while keeping other synthetic parameters constant.Figure 1c shows the XRD pattern of the sample obtained by the reaction of acetate salts Na(CH 3COO)and Y(CH 3COO)3in BmimBF 4.It can be clearly observed that cubic NaYF 4could also be obtained without the existence of CF 3COO -.This indicates that the IL provided the fluorine source for the formation of NaYF 4by the decomposition of BmimBF 4,which compares well with the reported results that BF 4-ions are prone to thermal decomposition to produce F -at a certain temperature.34,35To further confirm it,another control experi-ment was carried out just by changing the molecular composition of the ILs.The XRD pattern (Figure 1d)shows that NaYF 4couldFigure 1.(a)XRD pattern of NaYF 4synthesized via the reaction of trifluoroacetate precursors in BmimBF 4.(b)XRD pattern of NaYF 4synthesized via the reaction of trifluoroacetate precursors in BmimPF 6.(c)XRD pattern of NaYF 4synthesized via the reaction of acetate precursors in BmimBF 4.(d)XRD pattern of the product synthesized via the reaction of trifluoroacetate pre-cursors inBmimBr.Figure 2.(a)SEM image of the NaYF 4nanoclusters obtained inBmimBF 4.(b)TEM image of two NaYF 4nanoclusters obtained in BmimBF 4and the ED pattern (inset).(c)HRTEM image taken on the edge of a NaYF 4nanocluster.Scheme 1.Schematic Representation of the Formation of NaYF 4Nanocrystals Obtained in DifferentILsTable 1.Average Diameters of the NaYF 4Nanoclusters Obtained via the Reaction of Different Amounts of Trifluoroacetate Precursorsin BmimBF 4sampleNa(CF 3COO)/mmolY(CF 3COO)3/mmolaverage diameters/nm 10.50.530220.250.2516330.10.179(33)Ge,J.P.;Hu,Y.X.;Biasini,M.;Beyermann,W.P.;Yin,Y.D.Angew.Chem.,Int.Ed.2007,46,4342.(34)Fox,D.;Gilman,J.;Long,H.D.;Trulove,P.J.Chem.Thermodyn.2005,37,900.(35)Koval’chuk, E.;Reshetnyak,O.;Kozlovs’ka,Z.;B z a’ejowski,J.;Gladyshevs’kyj,R.;Obushak,M.Thermochim.Acta 2006,444,1.Article Chen et al.not be synthesized under the same condition by the use of trifluoroacetate salts (Na(CF 3COO)and Y(CF 3COO)3)and IL bearing bromide (BmimBr),and no signal of fluorine was detected by EDS for the final product (Figure 4a,b),which also pointed out that CF 3COO -did not decompose during the micro-wave heating process and did not provide the indispensable F -for the preparation of NaYF 4.The results of the above experiments illuminated that BmimBF 4not only served as the solvent and microwave absorbent in the whole synthetic process,but also acted as the building block and the major fluorine source for the formation of NaYF 4nanoclusters.Based on the above analysis,it is reasonable to deduce that NaYF 4nanocrystals may also be synthesized in other ILs bearing fluorine.So we applied the same synthetic procedure to prepare NaYF 4nanocrystals in BmimPF 6.As we expected,the XRD pattern (Figure 1b)shows that cubic NaYF 4could be achieved,but a peak of NaF was observed at 38.4°in 2θvalue.This probably could be explained as follows:The thermal degradation of BmimPF 6is relatively easier than that of BmimBF 4,36because the bond energy of P -F is weaker compared with that of B -F.19Therefore,high concentration of fluoride ions could be presented in the system of BmimPF 6,which might lead to the formation of NaF.The TEM image in Figure 5a illustrates that spherical to ellipsoidal nanoparticles could be obtained in BmimPF 6.The interplanar spacing shown in the HRTEM image (Figure 5b)is about 0.31nm corresponding to the (111)facets of cubic NaYF 4,which confirms that the nanoparticles are single crystals with high crystallinity.By comparison of Figure 2b and Figure 5a,we caneasily see that the morphology of the NaYF 4nanocrystals obtained in BmimPF 6is different from that of the nanoclusters obtained in BmimBF 4.This may be caused by the different viscosities of these two ILs.As is reported by Afonso´s group,the viscosity of BmimPF 6is higher than that of BmimBF 4.37Thus the assembly and aggregation of the small nanoparticles might be prevented to some extent in BmimPF 6,thus affecting the final morphology.In order to elucidate the effect of microwave dielectric heating on the preparation of the NaYF 4nanoclusters,the comparison between the samples synthesized through the ionothermal method and the microwave method was investigated.The XRD pattern (Figure S1in the Supporting Information)indicates that the product of the ionothermal treatment is cubic NaYF 4.TEM images (Figure S2in the Supporting Information)show that the aggregates of NaYF 4nanoparticles could also be obtained.However,the shape of these aggregates is not as regular as the spherical nanoclusters obtained through the microwave method.At the same time,some rectangular structures could also be observed in the same sample.The existence of different structures in the product may have resulted from the thermal gradients in the ionothermal reaction system.The vessel for the ionothermal reaction serves as an intermediary in the whole process,through which the energy could transfer from the oven to the solvent and then to the reactants.This could result in thermal gradients throughout the bulk solution,which lead to the formation of nonuniform reaction conditions.12However,the effect of thermal gradients could be eliminated in the microwave-accelerated system,which leads to the uniform morphology of the NaYF 4nanocrystals.The UC emission can be realized by doping cubic NaYF 4with lanthanide ions.The morphologies of the UC nanocrystals are not affected by doping with Ln 3þ(Figure 6).Figure 7a,b shows the fluorescence spectra for a 1wt %colloidal solution of NaYF 4:20%Yb 3þ,2%Er 3þand NaYF 4:20%Yb 3þ,0.2%Tm 3þin these two different ILs (BmimBF 4and BmimPF 6)under the excitation of a 980nm laser diode.The spectra of NaYF 4:Yb 3þ,Er 3þnanocrystals exhibit two emission bands,which could be attributed to 2H 11/2f 4I 15/2,4S 3/2f 4I 15/2,and 4F 9/2f 4I 15/2transi-tions of Er 3þ.The emission bands of NaYF 4:Yb 3þ,Tm 3þnano-crystals at 450-500nm and 630-670nm could be assigned to the 1G 4f 3H 6and 1G 4f 3F 4transition of Tm 3þ.38Interestingly,the UC emission intensity of nanoclusters obtained in BmimBF 4was enhanced nearly eight times compared with that of the nanopar-ticles in BmimPF 6.It is well-known that the UC intensity may be influenced by the surface state of nanoparticles.As the ratio of the surface defects decreases,the nonradiative decay is reduced,which would cause the increase of the emission intensity.39In our work,the formation of the NaYF 4nanoclusters might result in the surface reduction of the primary nanoparticles,which is caused by the hard connection among the nanoparticles formed during the self-assembling process.Therefore,the nonradiative centers existing on the surface of the nanocrystals will be eliminated partially,which finally enhances the intensity of the NaYF 4nanoclusters.40,41Figure 7c shows the strong UC lumi-nescence photographs for the 1wt %colloidal solution of the NaYF 4:20%Yb 3þ,2%Er 3þand NaYF 4:20%Yb 3þ,0.2%Tm 3þFigure 3.TEM images and corresponding size distributions of samples 1(a,b),2(c,d),and 3(e,f).(36)Huddleston,J.G.;Visser,A.E.;Reichert,W.M.;Willauer,H.D.;Broker,G.A.;Rogers,R.D.Green Chem.2001,3,156.(37)Branco,L.C.;Rosa,J.N.;Ramos,J.J.M.;Afonso,C.A.M.Chem.;Eur.J.2002,8,3671.(38)Wang,F.;Liu,X.G.J.Am.Chem.Soc.2008,130,5642.(39)Vetrone,F.;Naccache,R.;Mahalingam,V.;Morgan,C.G.;Capobianco,J.A.Adv.Funct.Mater.2009,19,2924.(40)Bovero,E.;van Veggel,F.C.J.M.J.Phys.Chem.C 2007,111,4529.(41)Mai,H.X.;Zhang,Y.W.;Sun,L.D.;Yan,C.H.J.Phys.Chem.C 2007,111,13721.Chen et al.Articlenanoclusters in BmimBF 4,implying that these nanoclusters are excellent UC hosts.The emission intensity of UC nanomaterials could be easily tuned just by changing the doping amounts of the lanthanide ions (Figure 8).For the NaYF 4:Yb 3þ,Er 3þnanoclus-ters obtained in BmimBF 4,the UC emission intensity obviously decreases when the concentration of Er 3þincreases from 0.2%to 2%with the Yb 3þconcentration fixed at 20%.For the NaYF 4:Yb 3þ,Tm 3þnanoclusters obtained in BmimBF 4,the UC emis-sion intensity also decreases with the increase of the Tm 3þconcentration from 0.2%to 2%,while keeping the concentration of Yb 3þat 20%.According to these results,it could be concluded that higher concentrations of Er 3þor Tm 3þmay cause concen-tration quenching of the spherical UC nanoclusters.41Further-more,we investigated how the size distribution affected the UC properties of the spherical NaYF 4:Yb 3þ,Er 3þ/Tm 3þnanoclus-ters.As shown in Figure 9,the UC emission intensity of NaYF 4:20%Yb 3þ,2%Er 3þand NaYF 4:20%Yb 3þ,2%Tm 3þde-creased when the average size of the nanoclusters was reducedfrom 302to 79nm.Because of the higher surface area of the smaller nanoclusters,14the nonradiative centers existing on the surface of the nanoparticles increased with the decrease of the size of the nanoclusters.Therefore,the UC emission intensity of the large nanoclusters would be enhanced compared with that of the small nanoclusters.The influence of different thermal treatment methods (microwave irradiation and ionothermal)on the UC prop-erties of the NaYF 4:20%Yb 3þ,2%Er 3þand NaYF 4:20%Yb 3þ,2%Tm 3þnanocrystals was also studied.The results (Figure S3in the Supporting Information)illuminated that the emission intensity of the UC nanocrystals synthe-sized via the microwave dielectric heating was slightly increased compared with that of the nanocrystals synthe-sized via the ionothermal method.The reason isthatFigure 4.(a)TEM image and (b)corresponding EDS spectrum of the product obtained inBmimBr.Figure 5.(a)TEM image,(b)HRTEM image,and (c)size dis-tribution of NaYF 4nanoparticles obtained in BmimPF 6.Figure 6.TEM images of (a)R -NaYF 4:20%Yb 3þ,2%Er 3þand(b)R -NaYF 4:20%Yb 3þ,0.2%Tm 3þnanoclusters obtained in BmimBF 4.TEM images of (c)R -NaYF 4:20%Yb 3þ,2%Er 3þand (d)R -NaYF 4:20%Yb 3þ,0.2%Tm 3þnanoparticles obtained in BmimPF 6.Article Chen et al.relative higher crystallinity and uniformity of the nano-clusters could be achieved through the microwave irradia-tion,which resulted in the increase of the UC emission intensity.26,294.ConclusionIn summary,we have developed a rapid microwave-assisted process to synthesize cubic NaYF 4in fluorine-contained ILs.It shows that small nanoparticles could form spontaneously in BmimBF 4due to the microwave irradiation,and then spherical cubic NaYF 4nanoclusters could be obtained by the self-assembly of these primary nanoparticles.From the control experiments with different precursors or ILs,it can be concluded that ILs play key roles,such as the solvent for the reaction,the absorbent of microwave irradiation,and the source of fluoride ions for the formation of NaYF 4nanocrystals.By the investigation ofdifferent thermal treatment methods,it is also found that higher crystallinity and uniformity of the nanocrystals could be achieved in the microwave-accelerated system.The various experimental results of the UC properties indicate that the NaYF 4:Yb 3þ,Er 3þand NaYF 4:Yb 3þ,Tm 3þnanoclusters synthesized in BmimBF 4exhibit excellent luminescent properties.Therefore,the rare earth fluoride nanoclusters are expected to be applied in solid-state laser,three-dimensional flat-panel displays,light emitting diodes,and some other optics devices.Since this IL-based and micro-wave-accelerated procedure is efficient and environmentally be-nign,it may have some potential applications in the synthesis of other nanomaterials.Acknowledgment.Grants-in-aid from NSFC (20821091,20961005,and 20971005)and MOST of China (2006CB601104)are gratefullyacknowledged.Figure 7.(a)UC luminescence spectra of R -NaYF 4:20%Yb 3þ,2%Er 3þnanoclusters in BmimBF 4and R -NaYF 4:20%Yb 3þ,2%Er 3þnanoparticles in BmimPF 6.(b)UC luminescence spectra of R -NaYF 4:20%Yb 3þ,0.2%Tm 3þnanoclusters in BmimBF 4and R -NaYF 4:20%Yb 3þ,0.2%Tm 3þnanoparticles in BmimPF 6.(c)UC luminescence photographs for 1wt %colloidal solution of R -NaYF 4:20%Yb 3þ,2%Er 3þ(left)and R -NaYF 4:20%Yb 3þ,0.2%Tm 3þ(right)nanoclusters in BmimBF 4.Figure 8.(a)UC luminescence spectra of R -NaYF 4:Yb 3þ,Er 3þnanoclusters with different doping concentrations of Er 3þ.(b)UCluminescence spectra of R -NaYF 4:Yb 3þ,Tm 3þnanoclusters with different doping concentrations of Tm 3þ.Figure 9.(a)UC luminescence spectra of R -NaYF 4:20%Yb 3þ,2%Er 3þnanoclusters with different average diameters.(b)UC luminescencespectra of R -NaYF 4:20%Yb 3þ,2%Tm 3þnanoclusters with different average diameters.。

一种微波辅助尿素水解制备ceo2 纳米实心球的方法

一种微波辅助尿素水解制备ceo2 纳米实心球的
方法
利用微波辅助尿素水解制备ceo2 纳米实心球是一种高效、快捷、绿色化的合成方法。

这种方法利用微波辅助尿素在酸性环境中把乙醇氧化为乙酸乙酯，然后迅速通过水解反应生成乙酸，乙酸又经历接下来的氧化反应生成ceo2 纳米实心球。

ceo2 纳米实心球主要有两种尺寸：直径约为300 奈米和20 奈米。

在微波辅助尿素水解方法制备ceo2 纳米实心球的过程中，一般使用的酸性溶剂主要有硫酸和氢氟酸，两种酸性溶剂都可以提高ceo2 纳米实心球的结晶度并能有效进行ceo2 的氧化反应。

然而，在水解步骤中，尿素溶液的pH 值越高，ceo2 的结晶性越低；如果把pH 值调低过多，则可能会使ceo2 过度结晶，影响微米实心球的性能。

在实验过程中，通常使用水为提取剂，把ceo2 纳米实心球从溶液中提取出来，并经过洗涤、干燥等处理。

洗涤可以去除余留的酸性溶剂，减少杂质的干扰；干燥过程可以控制ceo2 纳米实心球的粒度。

总的来说，以上微波辅助尿素水。

多元醇法合成银纳米线 ppt课件

2. Introduction to synthesis of silver nanowires
3. Synthesis of silver nanowires based on the polyol method
• 3.1 Introduction to the polyol method • 3.2 Mechanism • 3.3 Improvements of the polyol method • 3.4 Further research
3.3 Improvements
Several key factors
Formation of MTPs :
Requiring a low concentration of AgNO3
Etching of MTPs:
Requiring reducing the effct of oxygen on the activity of MTPs
Biomdeidcal and chemical sensor
Catalysts
……
Silver nanowires rafts for trace analysis
Optical negative refraction
ppt课件
5
Jie Yao, et al.Science,2008,321,930
2.Introduction to synthesis of silver nanowires
Approaches for synthesis of silver nanowires generally fall into one of two categories:
Template-directed
PVP

微波辅助多元醇法快速制备Ag纳米线的研究

作为太阳能电池的电极材料，沉积时不会破坏底部
成Ａｇ纳米线。考察了控制剂、微波功率和反应时间等条件对产物Ａｇ纳米线的影响，并对Ａｇ纳米线
的形成机理进行探讨。
ｌ买验
１．１实验试剂
微波辅助多元醇法快速制备Ａｇ纳米线的研究
郭瑞萍，郑敏，章海霞
（太原理Ｔ大学ａｔ．材料科学七ｊＴ程学院；ｂ．信息化管理与建设中心；Ｃ．新材料界面科学与丁程教育部重点实验室，太原０３００２４）
１．２样品制备首先，配置０．０８ｍＩ４ＦＩＩＩＩ１０１ＣｕＣ１２ＥＧ溶液，
探测范围等。目前，如何制备得到高质量的Ａｇ纳
米线成为研究人员关注的热点。用于制备Ａｇ纳米线的方法有多种，包括多元
第４４卷
第１期
太
原
理
工
大
学
学Байду номын сангаас
报
Ｖｏ１．４４Ｎｏ．１
２０１３年１月
Ｊ（）ＵＲＮＡＩＯＦＴＡ１ＹＵＡＮＵＮＩＶＥＲＳＩＴＹＯＦＴＥ（：ＨＮ（）Ｉ（）ＧＹ
Ｊａｎ．２０ｌ３
文章编号：１００７９４３２（２０１３）０１－００７６－０５
摘要：采用微波辅助多元醇法，以乙二醇为溶剂和还原剂，ＰＶＰ为表面活性剂．ＣｕＣｌ：为控制

多元醇法制备CoNi纳米粒子的形成机制_尺寸控制及磁性能

秦高梧1 ,裴文利1 ,姚骋1 ,任玉平1 , Y. M . L ee2(1 .东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110004 ;2. School of Nano and A dvanced Material s Engineering ,Changwo n Nati o n al U n iver s it y , G yeo n gnam 6412773 , K orea)摘要: 采用多元醇法在150 ～190 ℃合成了C o Ni 合金纳米粒子,利用S EM2ED X , XRD 和V SM 对所制备的C o Ni 纳米粒子形貌成分结构以及磁性能进行了研究,并进一步探讨了形核剂K2 Pt Cl4 对C o Ni 纳米粒子形貌及磁性能的影响。

结果表明, 在180 ℃用多元醇法制备的C o40 Ni60 (i n at %) 纳米粒子为F CC 结构, C o2 + 要易于Ni2 + 被还原,导致最初10 mi n 内合成的C o Ni 纳米粒子中含有约78 % ( 原子分数) C o ,表现为高饱和磁化强度和高矫顽力,随着反应时间的延长, C o Ni 纳米粒子的C o 含量饱和磁化强度及矫顽力逐步下降。

在150 ～190 ℃范围内, 随着反应温度的提高,Ni2 + 的被还原能力增强,高温下合成的C o Ni 纳米粒子具有较低的饱和磁化强度和较小的矫顽力。

形核剂K2 Pt Cl4 的加入,并不影响C o Ni 合金纳米粒子的成分和晶体结构。

但是, 随着形核剂浓度的增加, C o Ni 纳米粒子平均直径明显减小,其矫顽力有所增大。

通过设计形核剂的浓度, C o Ni 纳米粒子的直径可以在96～580 n m 范围内任意控制。

关键词: C o Ni 纳米粒子;多元醇法;形核剂;磁性能相应磁性能之间的关系,至今认识有限。

是故,本研究拟通过多元醇化学法制备不同粒径的C o Ni 合金纳米粒子,研究这些C o Ni 纳米粒子的磁性能与尺寸及成分之间的关系,以期对该类合金纳米粒子的形成机理有进一步的了解。

多元醇还原制备纳米Co粉及其磁性的研究

多元醇还原制备纳米Co粉及其磁性的研究刘飚;官建国;王琦;张清杰【期刊名称】《功能材料》【年(卷),期】2005(036)007【摘要】采用二价钴盐为前驱物,1,2-丙二醇为还原剂,用液相还原法制备了晶粒尺寸约为10～13nm、具有面心立方(β相)结构的纯度高、粒度均匀的纳米钴粉,运用XRD、TEM等分析方法对制备的纳米钴粉进行物相和结构形貌的表征,初步研究了多元醇法还原Co纳米粉的反应机理.采用VSM对纳米钴粉进行磁学性能的表征.结果表明,所制备的纳米Co粉在室温下具有铁磁性,并且矫顽力不高(6.282×103A/m).【总页数】4页(P1122-1125)【作者】刘飚;官建国;王琦;张清杰【作者单位】济南大学,材料科学与工程学院,山东,济南,250022;武汉理工大学,材料复合新技术国家重点实验室,湖北,武汉,430070;武汉理工大学,材料复合新技术国家重点实验室,湖北,武汉,430070;济南大学,材料科学与工程学院,山东,济南,250022;武汉理工大学,材料复合新技术国家重点实验室,湖北,武汉,430070;武汉理工大学,材料复合新技术国家重点实验室,湖北,武汉,430070【正文语种】中文【中图分类】O613.61;TB383【相关文献】1.多元醇法制备纳米Fe3O4及其静磁性能的研究 [J], 刘飚;官建国;张清杰2.利用还原共沉淀法制备纳米四氧化三铁磁性粉体 [J], 王缓;徐利华;邸云萍;张菡3.多元醇液相还原法制备纳米α-Fe_2O_3铁粉的研究 [J], 刘战伟4.纳米洋葱碳的制备及其微波吸收特性研究FeYO3/Y2O3∶ 1% Eu3 +,1% Tb3 +粉体的制备及其磁性研究 [J], 高泽宇;王佳玮;梁颖;张卫珂;杨艳青;张玉军5.多元醇还原法制备NiPd磁性纳米合金 [J], 艾凡荣;姚爱华;黄文旵;王德平;张欣因版权原因，仅展示原文概要，查看原文内容请购买。

微波辅助合成纳米材料的研究进展

微波辅助合成纳米材料的研究进展近年来，微波辅助合成纳米材料成为了研究的热点之一。

微波辅助的特殊合成方式可以有效地实现短时间内高效率的纳米材料制备，因此已经广泛应用于材料科学和纳米科技领域。

本文将介绍微波辅助合成纳米材料的相关技术和研究进展。

一、微波辅助合成纳米材料的基本原理微波辅助合成的核心是利用微波辐射对材料的物理和化学性质进行改变，以实现快速反应和高效率合成。

与传统合成方法相比，微波辅助合成具有以下特点：1.微波辐射可以快速加热样品，在短时间内使反应体系达到高温高压条件，促进反应物分子之间的碰撞和反应。

2.微波加热可以使反应体系实现均匀加热，进一步提高合成效率和产物纯度。

3.微波加热可以减少制备过程中的能量损失，避免产生废气、废水等二次污染。

二、微波辅助合成纳米材料的技术微波辅助合成纳米材料的技术主要包括微波水热法、微波辅助溶剂热法、微波辅助溶胶-凝胶法、微波辅助凝胶转化法等。

下面将简单介绍每种技术的优缺点及适用范围。

1.微波水热法微波水热法是一种高效率、低成本和易于控制的纳米材料制备方法，主要用于合成氧化物、羟基磷灰石等无机纳米材料。

由于水的高介电常数和低损耗，微波水热反应易于实现加热、溶解和离子交换等反应。

2.微波辅助溶剂热法微波辅助溶剂热法是一种新兴的纳米材料制备方法，主要用于合成金属氧化物、金属硫化物等纳米材料，其优点在于由于微波辐射可以提高反应速率，因此可以在低温下实现高效率合成。

然而，由于需要利用有机浸润剂来辅助反应，也会造成环境污染。

3.微波辅助溶胶-凝胶法微波辅助溶胶-凝胶法是一种有效且简便的氧化物、硅酸盐纳米材料制备方法。

该方法主要步骤包括：通过水解反应制备前驱体溶胶，然后通过微波辐射处理促进溶胶凝胶和固化成型。

此法存在高效、低成本等优点，且适合制备中等温度下的氧化物、硅酸盐体系。

4.微波辅助凝胶转化法微波辅助凝胶转化法是一种涉及凝胶制备和高温烧结的复杂计算机过程，主要用于合成金属氧化物、金属硫化物、金属氟化物等材料。

多元醇法制备CoNi纳米粒子的形成机制,尺寸控制及磁性能

分和晶体结构。但是，着形核剂浓度的增加，ｏ随ＣＮｉ纳米粒子平均直径明显减小，其矫顽力有所增大。通过设计形核剂的浓度，ｏ纳米粒子的直径可以在ＣＮｉ
９～５０ｍ范围内任意控制。６８ｎ
同时间后空冷，用丙酮，精和水分别洗涤后用于结利酒
的ＣＮｉ米粒子中含有约７（子分数）ｏ表现ｏ纳８原Ｃ，为高饱和磁化强度和高矫顽力，着反应时间的延长，随
ＣＮｉ米粒子的Ｃｏ纳ｏ含量、饱和磁化强度及矫顽力逐
地应用在微波吸收材料领域ｒ。这种薄膜的显著特点】］是在高频区（约几百ＭＨｚ具有高电阻率和高磁导率，）决定这种薄膜磁导率的因素有各向异性场、磁场和退粒子的尺寸等。随着工作频率提高至ＧＨｚ波段，述上
关键词：ＣＮｉ米粒子；元醇法；核剂；性能ｏ纳多形磁中图分类号：Ｔ３Ｇ１文献标识码：Ａ文章编号：０１９３（０００－１１０１０－７１２１）１０３－４
１引言
把直径为几十微米的软磁粒子镶嵌在高分子基体中形成几百微米厚的薄膜可以获得高磁导率，成功并
２ＳｈｏｆＮａｏａｄＡｄａｃｄＭａｅｉｌｇｎｅｉｇ，ａｗｏｔｎａｉｅｓｔ．ｃｏｌｏｎｎｖｎｅｔｒａｓＥｎｉｅｒｎＣｈｎｇｎＮａｉｌＵｎｖｒｉｙ，Ｇｙｏｇａ６１７３，ｒａｏｅｎｎｍ４ — ７Ｋｏｅ）

微波辅助溶剂热合成TiO2BiOI纳米纤维及其光催化活性研究

第４０卷湖北师范大学学报（自然科学版）Ｖｏｌ４０第４期ＪｏｕｒｎａｌｏｆＨｕｂｅｉＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ（ＮａｔｕｒａｌＳｃｉｅｎｃｅ）Ｎｏ４，２０２０微波辅助溶剂热合成ＴｉＯ２／ＢｉＯＩ纳米纤维及其光催化活性研究黄章律，胡学成，王国宏（湖北师范大学化学化工学院，湖北黄石　４３５００２）摘要：以钛酸四丁酯（ＴＢＯＴ）和五水合硝酸铋作为前驱体，利用静电纺丝和微波合成技术制备了不同ＴｉＯ２与ＢｉＯＩ质量比（Ｒ）的复合纳米纤维，并通过在可见光下降解罗丹明Ｂ（ＲｈＢ）水溶液评价其光催化活性。

实验结果表明，当Ｒ＝０．２时，ＴＢＦｓ２０具有最高的光催化活性（ｋ＝５３．３×１０－３ｍｉｎ－１），分别为纯ＴｉＯ２和ＢｉＯＩ的３．９倍和１．９倍。

这可能归因于在ＴｉＯ和ＢｉＯＩ相界面间形成的ｐ－ｎ异质结构，促进了光生电子２－空穴对的有效分离。

捕获实验证实了在光催化降解ＲｈＢ反应中超氧负离子（·Ｏ－）和空穴（ｈ＋）是主要２活性物质，并提出了一个增强光催化活性的ｐｎ机理。

关键词：ＴｉＯ２／ＢｉＯＩ；纳米纤维；ｐｎ异质结；光催化；ＲｈＢ中图分类号：Ｏ６１４．５文献标志码：Ａ文章编号：２０９６－３１４９（２０２０）０４－００４４－０９ｄｏｉ：１０．３９６９／ｊ．ｉｓｓｎ．２０９６－３１４９．２０２０．０４．００７０　引言随着人类社会的快速发展，迫切需要探索解决环境污染和能源短缺的新办法［１～３］。

半导体光催化技术被认为是一种将光能转化为化学能并降解水中污染物的有效策略，并引起了人们的广泛关注［４］。

尽管科学家们在开发高效光催化剂方面做了大量工作，但是由于单一光催化剂存在着光吸收范围窄、电子－空穴对复合速率快的缺点，限制了其在光催化领域的广泛应用。

为了解决这些问题，通过不同半导体构建异质结是一种潜在的有效策略。

目前已经研究出许多高效的异质结光催化剂，如ｇＣ３Ｎ４／ＴｉＯ２传统Ⅱ型异质结［５］、Ａｇ２Ｏ／ＴｉＯ２ｐｎ型异质结［６］、Ｂｉ３ＴａＯ７／ｇＣ３Ｎ４Ｚ型异质结［７］、ＮｉＯ／ＢｉＯＩＳ型异质结［８］。

微波辅助溶胶凝胶法制备BiTiO纳米粉体的方法[发明专利]

(10)申请公布号(43)申请公布日 (21)申请号 201410722421.5(22)申请日 2014.12.03C01G 23/00(2006.01)B82Y 30/00(2011.01)(71)申请人北方民族大学地址750021 宁夏回族自治区银川市西夏区文昌北路204号(72)发明人房国丽王立辉严祥辉(74)专利代理机构宁夏专利服务中心 64100代理人赵明辉(54)发明名称微波辅助溶胶凝胶法制备Bi 12TiO 20纳米粉体的方法(57)摘要本发明涉及一种微波辅助溶胶凝胶法制备Bi 12TiO 20纳米粉体的方法。

其特征在于，包括如下步骤：(1)将Bi(NO 3)3·5H 2O 加入到HNO 3溶液中，得到A 溶液；(2)将(CH 3(CH 2)3O)4Ti 加入到乙二醇中，得到B 溶液；(3)将A 溶液与步骤(2)得到的B 溶液混合，得到澄清C 溶液；(4)向C 溶液中加入柠檬酸；滴加氨水调节溶液的pH 值为6～10，并搅拌至成为透明溶胶；(5)将透明溶胶在100～130℃下缩合、干燥，得到干凝胶；(6)在低真空条件下，将得到的干凝胶通过微波加热分解。

本发明方法具有以下优点：工艺流程短，反应时间短，微波加热分解时间为7～15min，适用于工业化批量生产。

(51)Int.Cl.(19)中华人民共和国国家知识产权局(12)发明专利申请权利要求书1页说明书5页附图3页(10)申请公布号CN 104445382 A (43)申请公布日2015.03.25C N 104445382A1.一种微波辅助溶胶凝胶法制备Bi12TiO20纳米粉体的方法，其特征在于，包括如下步骤：(1)将Bi(NO3)3·5H2O加入到HNO3溶液中，并搅拌至完全溶解，得到A溶液；(2)将(CH3(CH2)3O)4Ti加入到乙二醇中，并搅拌至完全混合均匀，得到B溶液；(3)在搅拌的情况下，将步骤(1)得到的A溶液与步骤(2)得到的B溶液混合，得到澄清C溶液；(4)在继续搅拌条件下，向C溶液中加入柠檬酸，搅拌至完全溶解并且混合均匀；在继续搅拌条件下，滴加氨水调节溶液的pH值为6～10，并搅拌至成为透明溶胶；(5)将步骤(4)得到的透明溶胶在100～130℃下缩合、干燥，得到干凝胶；(6)在低真空条件下，将得到的干凝胶通过微波加热分解，即得到浅黄色的Bi12TiO20粉体。

碳纳米点合成(微波法)

碳纳米点合成（微波法）【实验目的】1、了解碳纳米点的基本性质（发光性质等）及应用前景2、掌握微波法制备碳纳米点的操作过程【实验仪器】微波炉（提供微波加热），手提式紫外分析仪，去离子超纯水机，电子天平【实验原理】近年来，由碳元素构成的各种纳米材料诸如富勒烯、石墨烯、碳纳米管和碳纳米点等不断被发现，碳纳米材料以其优良的性质成为21世纪科技创新的前沿领域。

尤其作为一种新型的碳纳米材料，碳纳米点因具有良好的水溶性、稳定性、低毒性、耐光漂白以及很好的生物相容性，正引起人们极大的关注，有望替代有机染料和多含重金属元素的半导体量子点在生物成像与传感、光催化及光电器件等领域的应用。

作为新型碳纳米材料，碳纳米点以其优异的物理和化学性质吸引了国内外学者的广泛关注和研究。

为制备出荧光性能优良的碳纳米点，世界各国研究人员已经建立了多种制备碳纳米点的新方法。

其中，微波技术已经成为一种重要的合成碳纳米点的化学手段。

例如，2009年，Zhu等人报道了一种简单、经济的制备荧光碳纳米点的微波辅助热解法，具体过程为：将一定量的聚乙二醇（PEG-200）和糖类物质（葡萄糖和果糖等）溶解在蒸馏水中形成透明溶液，然后将该溶液在微波炉中加热，随着反应的进行，溶液颜色由无色逐渐变为黄色，最后为黑色，即得到了荧光碳纳米点。

通过改变微波处理时间，可以很好地控制碳纳米点的尺寸及发光特性。

微波处理时间越久，碳纳米点尺寸越大，发光向长波长移动。

【实验内容】1、将1 g柠檬酸和1 g（2 g）尿素溶于20 mL去离子水中形成透明溶液；2、将混合溶液放入750 W的微波炉中微波加热15 min左右，在此过程中反应液从无色溶液逐渐变为淡棕色溶液最后变为深褐色粘稠状固体，表明形成了碳纳米点；3、取少量反应产物溶于去离子水中，置于紫外分析仪下，分析两种碳纳米点样品的发光特性。

【注意事项】1、药品称量需认真，以免所制备的两种碳纳米点的发光性质差别不明显；2、微波加热的时间要掌握好，加热时间太短或太长都会影响碳纳米点质量和发光性质。

纳米材料的化学合成法

溶胶—凝胶法的优缺点优点： ①操作温度低，节约能源，使得材料制备过程易于控制； ②高度均匀、可变性大； ③工艺简单，易于工业化，成本低，应用灵活； ④可提高生产效率； ⑤可保证最终产品的纯度. 缺点： ①凝胶颗粒之间烧结性差，块体材料烧结性不好；
②干燥时收缩大。
基本原理：
1.4、水热法
水热法是在高压釜里的高温、高压反应环境中，采用水作为反应介质，使得通常难溶或不溶的物质溶解，反应还可进行重结晶。水热技术具有两个特点，一是其相对低的温度，二是在封闭容器中进行，避免了组分挥发。
银等
水热沉淀法例如 KF+MnCl2 - KMnF2
设备
1.5、溶剂热合成法
基本原理：
用有机溶剂（如：苯、醚）代替水作介质，采用类似水热合成的原理制备纳米微粉。非水溶剂代替水，不仅扩大了水热技术的应用范围，而且能够实现通常条件下无法实现的反应，包括制备具有亚稳态结构的材料。
溶剂热法分类
1.9、模板合成法
基本原理：
利用基质材料结构中的空隙作为模板进行合成。结构基质为多孔玻璃、分子筛、大孔离子交换树脂等。例如将纳米微粒置于分子筛的笼中，可以得到尺寸均匀，在空间具有周期性构型的纳米材料
1.10、电解法
基本原理：
电解包括水溶液电解和熔盐电解两种。用此法可制得很多用通常方法不能制备或难以制备的金属超微粉，尤其是电负性较大的金属粉末。还可制备氧化物超微粉。用这种方法得到的粉末纯度高，粒径细，而且成本低，适于扩大和工业生产。
溶剂热法常用溶剂
溶剂热反应中常用的溶剂有:乙二胺、甲醇、乙醇、二乙胺、三乙胺、吡啶、苯、甲苯、二甲苯、1. 2 - 二甲氧基乙烷、苯酚、氨水、四氯化碳、甲酸等.

微波辅助的多元醇法合成CoNi纳米材料_英文_

lic nanostructures with very narrow size distributions [15,16]. CuNi [17], AuAg [18], PdPt [19], AuNi [20], and NiCo [21] spherical or core-shell nanoparticles with rather narrow size distributions have been obtained by the microwave heating technique. We have previously synthesized CoNi nanorods/nanowires by a conventional hydrothermal process, but the synthesis required up to 12 h [3]. In this work, we used a microwave-assisted polyol procedure to fabricate CoNi nanourchins and nanowires in a very short time and the morphology was effectively controlled by simply tuning the temperature and heating rate.
1 Experimental
1.1 Materials synthesis
Microwave heating was carried out using a multimode 2.45 GHz microwave apparatus (MARS-5, CEM Corporation). The temperature of the reaction solution was measured by a fiber optic thermometer that was directly inserted into the solution. The CoNi nanoparticles with the molar ratio of 4:1 were prepared by a heterogeneous nucleation method in 1,2-propanediol described elsewhere [3]. In a typical synthesis, 0.8 g Co(OAc)2·4H2O, 0.2 g Ni(OAc)2·4H2O, and 0.2 g NaOH were dissolved into 50 ml 1,2-propanediol, followed by the addition of 0.27 g (0.95 mmol) stearic acid and 0.02 g (0.18 mmol) RuCl3·xH2O (35 wt% Ru) dissolved in 5 ml 1,2-propanediol. Subsequently, the mixture was transferred into a flask (100 ml) and heated to the desired temperatures (140–170 oC) at 10 oC/min and kept at that temperature for 2 h. The black powders obtained was centrifuged, thoroughly washed with ethanol, and dried at 50 oC for 5 h under vacuum. The key parameters of the temperature, heating rate, and synthesis time were studied.

微波辅助polyol法制备纳米金属镍及磁性研究

方面已经被广泛应用Ｄ６。一，３般说来，镍颗粒中所有原子的磁矩，向一致的线性排取
列着，形成单畴。然而，随着颗粒尺寸的减小，磁晶其各向异性能如不能遏止热扰动（Ｔ）就会引起由铁ＫＢ，
Ｎ纳米球具有典型的铁磁性。ｉ
２实验与测量
在一个１０的玻璃烧瓶中配制含０１５ｌＬ０ｍｌ．２ｍｏ／
关键词：单分散Ｎｉ；波辅助ｐｌｏ还原法；球微ｏｙｌ磁性中图分类号：０４２５８．４文献标识码：Ａ
范围在５Ｏｍ、Ｏ～１０ｍ的单分散Ｎｉ，～ｌｎ１０８ｎ球对其磁性进行了测量分析。用ＸＲＤ和ＥＤＡＸ，着用ＴＭ接Ｅ
和ＭＦ分别对制备的样品进行测试，用ＶＳ和Ｍ并Ｍ
大且分布不均匀。微波ｐｌｏ还原法通常被用来制备ｏｙｌ粒径＞ｌＯｍ的单分散镍球颗粒［。最近我们使Ｏｎ１用微波辅助ｐｌｏ法，ｏｙｌ并加入表面活性剂，成功地制得了直径范围大约在５ｌｎ超顺磁）１０１０ｍ～Ｏｍ（、０～８ｎ（磁性单畴）铁的单分散Ｎｉ。研究了这种结构的磁球
其多种电磁特性或物理特性发生变化。在纳米磁性材
料中，属磁性纳米粒子，金以及具有核壳结构的球型粒子，近几年来受到了极大关注［］由于材料的结构与１。性质相关联，使其具有重要应用，比如超高密度记忆存储材料，纳米磁性装置，医药等［］３。金属Ｎｉ催化、 “ 在

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

Bimetallic CoNi nanoparticles have attracted increasing attention for their potential applications in ultra-high density magnetic recording, magnetic resonance imaging, and catalysis [1–3], where their performance strongly depend on the chemical composition, size, and morphology. Compared with conventional spherical particles, CoNi nanorods and nanowires exhibited enhanced activities due to the high shape anisotropy [4,5], which clearly demonstrated that the morphology of the bimetallic nanoparticles is an essential parameter determining the magnetic properties. Spherical CoNi nanoparticles were previously reported to be highly active for methane drying reforming [6] and for growing single-walled carbon nanotubes [7], but CoNi nanoparticles with anisotropic shapes as the catalyst has not been reported.
Microwave-Assisted Polyol-Synthesis of CoNi Nanomaterials
GUO Xiaohui, LI Yong, LIU Qiying, SHEN Wenjie*
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
lic nanostructures with very narrow size distributions [15,16]. CuNi [17], AuAg [18], PdPt [19], AuNi [20], and NiCo [21] spherical or core-shell nanoparticles with rather narrow size distributions have been obtained by the microwave heating technique. We have previously synthesized CoNi nanorods/nanowires by a conventional hydrothermal process, but the synthesis required up to 12 h [3]. In this work, we used a microwave-assisted polyol procedure to fabricate CoNi nanourchins and nanowires in a very short time and the morphology was effectively controlled by simply tuning the temperature and heating rate.
In contrast to conventional heating methods, microwave irradiation has been applied for the rapid synthesis of metal-
646
催化学报
Chin. J. Catal., 2012, 33: 645–650
1 Experimental
1.1 Materials synthesis
Microwave heating was carried out using a multimode 2.45 GHz microwave apparatus (MARS-5, CEM Corporation). The temperature of the reaction solution was measured by a fiber optic thermometer that was directly inserted into the solution. The CoNi nanoparticles with the molar ratio of 4:1 were prepared by a heterogeneous nucleation method in 1,2-propanediol described elsewhere [3]. In a typical synthesis, 0.8 g Co(OAc)2·4H2O, 0.2 g Ni(OAc)2·4H2O, and 0.2 g NaOH were dissolved into 50 ml 1,2-propanediol, followed by the addition of 0.27 g (0.95 mmol) stearic acid and 0.02 g (0.18 mmol) RuCl3·xH2O (35 wt% Ru) dissolved in 5 ml 1,2-propanediol. Subsequently, the mixture was transferred into a flask (100 ml) and heated to the desired temperatures (140–170 oC) at 10 oC/min and kept at that temperature for 2 h. The black powders obtained was centrifuged, thoroughly washed with ethanol, and dried at 50 oC for 5 h under vacuum. The key parameters of the temperature, heating rate, and synthesis time were studied.
Abstract: Co0.8Ni0.2 nanourchins and nanowires were fabricated by microwave-assisted polyol-synthesis. Their structural evolution was monitored by powder X-ray diffraction and transmission electron microscopy measurements. The nucleation and growth rates of the crystals in their formation mechanism were discussed. Their catalytic activity for glycerol hydrogenolysis depended on their anisotropic shape and particle size. Key words: microwave-heating; polyol-synthesis; cobalt; nickel; nanowire; nanourchin; glycerol hydrogenolysis
中国科学院大连化学物理研究所催化基础国家重点实验室, 辽宁大连 116023
摘要: 利用微波辅助的多元醇法合成出纳米线和海胆状结构 Co0.8Ni0.2, 采用 X 射线衍射和透射电镜技术对该材料合成过程中
的结构变化进行了详细的研究. 根据晶体的成核与生长速率阐述了 Co0.8Ni0.2 纳米结构的形成机理. 结果表明, Co0.8Ni0.2 纳米
2012
文章编号: 0253-9837(2012)04-0645-06
Chinese Journal of Catalysis
国际版 DOI: 10.1016/S1872-2067(11)60350-1
Vol. 33 No. 4
研究论文: 645~650
微波辅助的多元醇法合成 CoNi 纳米材料
郭小惠, 李勇, 刘琪英, 申文杰*
The control of the size and morphology during the synthesis of CoNi nanostructures has emerged as one of the most popular topics in materials science because of their magnetic and cataห้องสมุดไป่ตู้ytic properties. CoNi nanorods [4], nanowires [5], nanochains [8], nanoneedles [9], nanotube arrays [10], nanodumbbells [11], nanorings [12], and nano/micro-flowers [13] have been fabricated in the liquid phase with the aid of soft and hard templates. These advanced but, in many cases, complicated preparative techniques have greatly facilitated the shape control of CoNi nanomaterials, but they usually use conventional heating and the unavoidable temperature gradient adversely affected the particle size distribution and product yield [14].