简介:以钬酸四丁酯为前驱体、硝酸银作为银源,通过合适的配比以溶胶-凝胶(Sol-gel)法制备了纯TiO2m米粉体及不同银含量掺杂的TiO2m米粉体.采用XRD、TEM等方法对样品进行形貌分析和结构表征,XRD结果表明,掺杂银和未掺杂银的TiO2纳米粉体均为锐钬矿型,平均粒径约为9-13nm,适量银的掺杂有效抑制了TiO2粉体粒径的增大以及向金红石型的相转化.光催化活性测试分析结果表明,掺银TiO2比纯TiO2对有机染料亚甲基蓝光催化降解活性有了明显提高.
简介:Ca_3Co_2O_6,Na和Ni的电子结构做了模型被被基于的Camhride连续全部的精力包裹(CASTEP)的量化学药品软件学习,在密度函数理论(DFT)和伪潜力上。优点(Z)的电子传导性,seebeckcoefficient,热传导性和图被计算。精力乐队结构在做semiconductors.Na的模型shoivs由于代理杂质揭示杂质层次的形式p类型半导体的特性,而是做Ni的模型是n-typesemiconductor。计算结果证明做的模型的电的传导性比的高非--做的模型,当Seebeck系数和做的模型的热电导率是比非做的那些低的时。因为大增加,电的电导率,做Na的模型的Z被提高,热电的性质被改进。作为Seebeck系数的大衰落,在另一方面,Ni-的Z做了模型不到的非--做的模型。
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简介:ZnOnanoconearrays(NCAs)decoratedwithblackTiO2nanoparticles(BTiO2NPs)wereuniformlyanchoredonthesurfaceofcarboncloth(CC)directlybyasimplyelectrochemicaldepositionmethod.ThusanovelB-TiO2NPs/ZnONCAs-CChierarchicalheterostructurewasformed.Itdisplayedsuperiorperformanceandachievedahigherphotocurrentover0.4mA·cm^-2beforetheonsetofthedarkcurrent,attributedtotheseparationofthephotogeneratedelectron-holepair.BasedontheB-TiO2NPs/ZnONCAs-CCheterostructure,thecatalystwasfabricatedforpromotingtheseparationofchargecarriers.Moreover,theintroductionofTi^3+andoxygenvacanciesonthesurfaceofTiO2NPsexpandedtheabsorptionbandedgeandenhancedtheelectricalconductivityaswellasthechargetransportationonthecatalyticsurface.ItindicatesthattheB-TiO2NPs/ZnONCAs-CCcompositeisbeneficialtotheimprovementofthephotoelectrochemical(PEC)activity.
简介:Thesol-gelprocessofcitricacidchelatingwithmetalcationsforthesynthesisofnormalspinelLiMn2O4andthereactionmechanismwereinvestigatedbymeansofXRD,IR,TG-DTA,andSEM.Theresultsshowthatatthebeginninglithiumcitrateandchelatecompoundofcitricacidwithmanganeseionsformed,andthenwithheatingtheesterificationandcondensationreactionsoccuredbetweenthemandglycol.TheproductsobtainedarepolymersinwhichmetalcationsaredistributedhomogeneouslyonatomicscalethatensurehighreactivitytocationsofLi+andMn2+.Firingthegelpreparedbythisprocess,thelatticediffusionsofsolidreactantionscausedbynon-homogeneityofreactantsareeliminatedandavoided.At400℃phase-pureLiMn2O4withnanometerscalecrystallizationhavingprecisestoichiometryandperfectcrystallizationcanbeobtained.Themodelofchelatecoordinateofdouble-moleculebetweencitricacidandMn2+inthegelnetworkisproposed.ItisimportantforexplainingthedispersionstateofMn2+andtheformationprocessofgelbythismodel.
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简介:CdSe/CdS半导体量点共同敏化TiO2nanorod数组在透明的传导性的做氟的符号的听氧化物(FTO)上被制作使用热水、连续的离子的层吸附和反应(SILAR)过程的底层。样品的结构、词法的性质被X光检查描绘衍射(XRD),地排放扫描电子显微镜学(FESEM),和传播电子显微镜学(TEM)。结果显示CdSe/CdSQD在TiO2nanorods的表面上是一致地涂的。轻吸收边的移动被拿紫外可见的吸收系列监视。与TiO2nanorod数组的吸收系列相比,CdSe/CdSQD的免职转移吸收边到更高的波长。当在量点的co-sensitizers敏化太阳能电池(QDSSC),在CdSe/CdS/TiO2nanorod数组的可见光的区域的提高的轻吸收显示CdSe/CdS层能行动。由优化CdSe层免职周期,5.78mA/cm2的光电流,0.469V的开的电路photovoltage和变换,1.34%的效率在100mw/cm2的照明下面被获得。
简介:ThethermodynamicphasestabilityareadiagramsofBCl3-NH3-SiCl4-H2-ArsystemwereplottedviaFactsagesoftwaretopredictthekineticexperimentalresults.Theeffectsofparameters(ie,partialpressureofreactants,depositiontemperatureandtotalpressure)onthedistributionregionsofsolidphaseproductswereanalyzedbasedonthediagrams.Theresultsshowthat:(a)Solidphaseproductsaremainlyaffectedbydepositiontemperature.TheareaofBN+Si3N4phaseincreaseswiththetemperaturerisingfrom650to900℃,anddecreaseswiththetemperaturerisingfrom900to1200℃;(b)Whentemperatureandtotalpressureareconstants,BN+Si3N4phaseexistsatahighpartialpressureofNH3;(c)Theeffectoftotalsystempressureiscorrelatedtodepositiontemperature.Thetemperaturerangingfrom700to900℃underlowtotalpressureistheoptimumconditionforthedeposition.(d)Appropriatekineticparameterscanbedeterminedbasedontheresultsofthermodynamiccalculation.Si–B–Ncoatingisobtainedvialowpressurechemicalvapordeposition.TheanalysisbyX-rayphotoelectronspectroscopyindicatesthatB–NandSi–Narethemainchemicalbondsofthecoating.