BiVO4膜电极的制备及其光电化学性能.pdf

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1、物理化学学~E(WuliHuaxueXuebao12160ActaP．一Chim．Sin．2011，27(9)，2160—2166September[Article]www．whxb．pku．edu．cnBiVO4膜电极的制备及其光电化学性能彭天右柯丁宁曾鹏张晓虎范科(武汉大学化学与分子科学学院，武汉430072)摘要：以自制的BiVO纳米粉制备膜电极，采用电化学方法较系统地研究了退火温度和膜厚对BiVO膜电极的光电化学行为和电了输运与复合的影响．结果表明：退火温度和膜厚对BiVO膜电极的光电特性有显著的影响．膜厚为6．75lJm时，BiVO膜电极具有最

2、佳的光电化学特性．退火温度低于500。C时，膜电极的光电活性随着温度的升高而增强，至500。C时达到最大值：此后膜电极内的体相缺陷明显增加，导致其光电活性逐渐降低．BiVO膜电极有良好的可见光光电转换效率，并利用其单色光转换效率曲线计算得到BiVO的带隙为2．36eV，采用莫特一肖特基电化学法测得其平带电位为一0_7V(VSAg／AgCI)．上述结果为BiVO光催化体系的优化提供了重要的参考．关键词：BiVO膜电极：光电化学性能：瞬态光电流谱：半带电化中图分类号：0646PreparationandPhotoelectrochemicalPerforma

3、nceofBiVO4FilmElectrodePENGTian—YouKEDing—NingZENGPengZHANGXiao—HuFANKe(CollegeofChemistryandMolecularScience，WuhanUniversity,Wuhan430072，R．China)Abstract：ABiV0f¨melectrodewaspreparedusingahome—madeBiVOnanopowderandtheefectsofannealingtemperatureandf¨mthicknessonitsphotoelectroch

4、emicalbehavior．electrontranspo~andrecombinationintheBiVOelectrodeweresystematicallystudiedbyelectrochemicaItechniques．ExperimentalresultsindicatethattheannealingtemperatureandfiImthicknesscansignificantlyinfluencethephotoelectrochemicalcharacteristicsoftheBiVO4electrode．AtIOWanne

5、alingtemperature(s500。C)thephotoelectrochemicaIactivityimproveduponincreasingthetemperatureandtheoptimalactivitywasobtainedfortheelectrodeannealedat500。C．Athightemperature(>500。C)thephotoelectrochemicaIactivitydecreasedbecauseofamarkedincreaseofbulktrapsintheelectrode．TheBiVOelec

6、trodeshowedgoodphoton·to—electronconversioneficiencyundervisibleIightanditsbandgapwasfoundtobe2．36eVbasedOnanjncidentmonochromaticphoton．to．electricconversioneficiencycurve．Theflat．bandpotential()ofBiVO4wasdeterminedtObe—OI7V(VSAg／AgCI)bytheM6tt．Schottkymethod．Theseresultsgiveani

7、mportantreferencefortheoptimizationoftheBiVOphotocatalyticsystem．KeyWords：BiVOfilmelectrode；Photoelectrochemicalperformance；Transientphotocurrentspectrum；Flat—bandpotential1引言污染物等领域具有诱人的应用前景．其光催化过半导体材料在光催化劈裂水制氢或氧及降解程涉及光生载流子的氧化还原作用，机理上最重要Received：April6．201l：Revised：June5，201l：Pub

8、lishedonWeb：Julyl1，2011．Correspondingaut