Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (12): 2917-2923.doi: 10.3866/PKU.WHXB201209032

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

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).

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