Enhanced visible-light activation of peroxymonosulfate by novel Bi2O2SO4/Bi,N,S-TiO2 heterojunction toward efficient trichloroethylene degradation: Insight into function of Bi2O2SO4

The photocatalytic performance of Bi2O2SO4 (BOS) has not been widely noticed. In this work, a novel heterojunction of Bi2O2SO4/Bi, N, S-TiO2 (BOS/BNST) was synthesized. The heterojunction exhibited high efficiency for trichloroethylene (TCE) degradation. Degradation rate of TCE could be over 99% in 1 h, when concentration of TCE was 7 mg/L, and reaction rate constant could be 0.06573 min-1. The main reasons for the enhancement are depicted as follows: (1) TiO2 was doped with Bi, N and S, which enhanced the visible light response; (2) The combination of BOS and BNST improves the separation efficiency of photo-induced carriers; (3) Loading of BOS prompts PMS adsorption; (4) The Bi4+ and Bi3+ cycling in BOS/BNST facilitated PMS activation. This paper introduces a novel photocatalyst which exhibited excellent photoactivity, and provides a new perspective for the research of PMS activation under visible light.