物理化学学报 >> 2012, Vol. 28 >> Issue (12): 2917-2923.doi: 10.3866/PKU.WHXB201209032

催化和表面科学 上一篇    下一篇

盐酸溶液处理钒酸铋增强可见光催化活性及其机理

龙明策, 万磊, 曾曾, 刘伊依, 陈渊源   

  1. 上海交通大学环境科学与工程学院, 上海 200240
  • 收稿日期:2012-07-19 修回日期:2012-09-03 发布日期:2012-11-14
  • 通讯作者: 龙明策 E-mail:long_mc@sjtu.edu.cn
  • 基金资助:

    国家自然科学基金(20907031)资助项目

Enhanced Visible Light Activity of BiVO4 by Treating in HCl Aqueous Solution and Its Mechanism

LONG Ming-Ce, WAN Lei, ZENG Ceng, LIU Yi-Yi, CHEN Yuan-Yuan   

  1. School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
  • Received:2012-07-19 Revised:2012-09-03 Published:2012-11-14
  • Supported by:

    The project was supported by the Natural Science Foundation of China (20907031).

摘要:

采用盐酸水溶液处理BiVO4 的方法获得增强的光催化活性. 在0.1 mol·L-1 酸溶液中浸渍反应6 h,BiVO4 的可见光催化降解苯酚的活性提高了3.5 倍. 采用X 射线衍射(XRD), 扫描电镜(TEM)和漫反射光谱(DRS)等表征手段研究处理后样品的晶相组成和表面形貌, 结合不同酸和氯化物处理的对照实验, 结果表明,在H+和Cl-的协同作用下, BiVO4表面部分溶出并以BiOCl 沉积, 形成了表面具有凹陷沟壑的BiVO4颗粒与片状结构BiOCl 的复合物. 采用悬浮液光电压法测定BiOCl 平带电位, 通过BiVO4和BiOCl 的能带分析及其混合颗粒的光催化活性测试, 确证二者间不存在颗粒间电子转移效应. 增强的光催化活性主要归因于BiVO4表面形成了有助于光生电荷迁移的凹凸不平结构. 这种表面处理方法有望成为一种增强半导体化合物光催化活性的有效途径.

关键词: 光催化, BiVO4, BiOCl, 异质结, 表面纳米结构, 可见光活性, 苯酚降解

Abstract:

Enhanced photocatalytic activity of BiVO4 has been achieved by immersing in HCl aqueous solution. After treated for 6 h in 0.1 mol·L-1 HCl solution, the visible light activity of BiVO4 for phenol degradation increased by 3.5 times. X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS) were carried out to analyze the crystal components and surface morphology of the treated samples. Comparison of samples treated in different acids and chlorides indicated that with the appropriate concentrations of H+ and Cl- ions, BiVO4 partially dissolved, was deposited as BiOCl, and finally a composite of flaked BiOCl and micro-particles of BiVO4 with pits formed over the surface. The flatband potential of BiOCl was measured by a slurry method. According to the results of energy band analyses and photocatalytic activity tests of mixed BiVO4 and BiOCl particles, there is no interparticle electron transfer effect between them. Therefore, the mechanism of the enhanced photocatalytic performance of the treated BiVO4 can be attributed to the unevenness of the surface, which can facilitate photogenerated charge separation. This type of surface treatment method could be developed into an effective method for preparing photocatalysts with enhanced photocatalytic performance.

Key words: Photocatalysis, Bismuth vanadate, Bismuth oxychloride, Heterojunction, Surface nanostructure, Visible light activity, Phenol degradation

MSC2000: 

  • O643