Graphite-bridged indirect Z-scheme system TiO2–C–BiVO4 film with enhanced photoelectrocatalytic activity towards serial bisphenols

Abstract

Due to the increase in the occurrence of bisphenols (BPs) in the environments, it is urgent to develop efficient and ecofriendly methods for their removal. A novel, indirect Z-scheme TiO2–C–BiVO4 film was prepared by a sol-gel method combined with hydrothermal carbonization. The doped graphite carbon was generated in situ from glucose, which acted as an electron-transfer bridge for the Z-scheme system to enhance the heterojunction tightness between TiO2 and BiVO4. This resulted in an increasing separation efficiency of photogenerated electrons and holes and a stronger redox ability of the TiO2–C–BiVO4 film for the degradation and detoxification of BPs. The degradation efficiency of BPs was over 95% in 240 min, except for that of 4,4′-sulphonyldiphenol (BPS) due to the presence of the OSO group, and all of the BPs were nearly completely mineralized when the reaction time reached 360 min. Consequently, the inhibition ratio towards Vibrio fischeri decreased significantly along with the loss and mineralization of aromatic intermediates during photoelectrocatalytic degradation. 2,2-bis(4-Hydroxyphenyl) butane (BPB), 4,4’-(1-phenylethylidene)-bisphenol (BPAP), and (4,4′-hexafluoroisopropylidene) diphenol (BPAF), with relatively high toxicity levels and lipophilicity and as toxic product precursors, require attention in terms of environmental safety. Overall, this work provides a promising and environmentally friendly way to remove BPs from water.