BiVO4的光催化活性及其正电子湮没谱.pdfVIP

学兔兔 化 工 进 展 CHEMICAL INDUSTRY AND ENGINEERING PROGRESS 2009年第28卷第5期 BiVO4的光催化活性及其正电子湮没谱 刘自力1,2李 辉 ，秦祖赠 ，陈胜洲2柯 刚2 陈国术2梁 红 f 广西大学化学化工学院，广两 南宁530004； 广州大学化学化工学院，广东 广州510006) 摘 要：以2,4一二硝基苯酚光催化降解为探针反应，考察了BiVO4的光催化降解活性。利用正电子湮没谱分析了焙 烧温度对BiVO4光催化活性的影响。结果表明，焙烧温度能引起特定的缺陷数目变化，改变了光催化剂的微观结构。 经900℃焙烧的BiVO4催化剂比在其它温度下焙烧的催化剂有较多的表面缺陷数目，可产生表面光生电子一空穴的 数目较多，不均匀性、缺陷位的电子密度大，使得其光催化氧化活性增强，即2,4一二硝基苯酚的降解率较高。 关键词：钒酸铋；光催化；2,4一二硝基苯酚；正电子湮没谱；焙烧温度 中图分类号：O 643．36 文献标识码：A 文章编号：1000—6613(2009)05—0904—04 Photocatalytic activity of BiVO4 and its positron annihilation spectrum LIUZili ，-，LIHui ，QINZuzeng ，CHENShengzhou ，KEGang ，CHENGuoshu ，LIANGHong ( School of Chemistry and Chemical Engineering，Guangxi University，Nanning 530004，Guangxi，China； School ofChemistry and Chemical Engineering，Guangzhou University，Guangzhou 510006，Guangdong，China) Abstract：Positron lifetime technique iS one of a few methods sensitive to voids on the mono—atomic scale．The photocatalytic activity of BiVO4 was studied when the degradation of 2,4一dinitrophenol was used as a probe reaction．The effect of calcination temperature on the photocatalytic activity of BiVO4 was analyzed by posi~on annihilation spectrum．The results showed that the amount of surface defects and the microstructure of photocatalyst changed with the calcination temperature．More surface defects， amount of photo produced electrons—hole，heterogeneity and the electronic density of defect sites were found on BiVOd calcined at 900℃ than other temperatures，which increased the photocatalytic oxidation activity of BiVOd，that iS，the degradation rate of 2,4一dinitrophenol was