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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.
简介:通过溶胶凝胶-熔盐法以NaCl为熔盐制备了掺杂Co^2+的Cd1-xCoxFe2O4(x=0~0.5)尖晶石型铁氧体。利用XRD、SEM和VSM等手段对样品进行了结构、形貌和磁性表征,并详细讨论了Co^2+对Co1-xCdxFe2O4(x=0-0.5)铁氧体结构和磁性的影响。结果表明:在研究范围内掺杂后仍然能得到单相尖晶石结构铁氧体;样品均为正八面体;比饱和磁化强度随x的增大而增加。