Chinese Journal of Catalysis ›› 2015, Vol. 36 ›› Issue (12): 2145-2154.DOI: 10.1016/S1872-2067(15)60986-X

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Substrate-dependent photoreactivities of BiOBr nanoplates prepared at different pH values

Zhihui Ai, Jilin Wang, Lizhi Zhang   

  1. Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, Central China Normal University, Wuhan 430079, Hubei, China
  • Received:2015-08-24 Revised:2015-09-19 Online:2015-12-02 Published:2015-12-07
  • Supported by:

    This work was supported by the National Natural Science Funds for Distinguished Young Scholars (21425728), the National Natural Science Foundation of China (21173093, 21177048, 21273088, 21477044), the Key Project of Natural Science Foundation of Hubei Province (2013CFA114), and the the Fundamental Research Funds for the Central Universities (CCNU14Z01001 CCNU14KFY002).

Abstract:

In this study, we showed that BiOBr nanoplates prepared at different pH values have substrate-dependent photocatalytic activities under visible-light irradiation. The BiOBr nanoplates synthesized at pH 1 (BOB-1) degraded salicylic acid more effectively than did those obtained at pH 3 (BOB-3), but the order of their photocatalytic activities in rhodamine B (RhB) degradation were reversed. Electrochemical Mott-Schottky and zetα-potential measurements showed that BOB-1 had a more positive valence band and lower surface charge, leading to superior photocatalytic activity in salicylic acid degradation under visible light. However, BOB-3 was more powerful in RhB degradation because larger numbers of superoxide radicals were generated via electron injection from the excited RhB to its more negative conduction band under visible-light irradiation; this was confirmed using active oxygen species measurements and electron spin resonance analysis. This study deepens our understanding of the origins of organic-pollutant-dependent photoreactivities of semiconductors, and will help in designing highly active photocatalysts for environmental remediation.

Key words: Degradation, Visible light, Substrate dependent photoreactivity, Bismuth oxybromide nanoplate, Rhodamine B, Salicylic acid