Efficient water disinfection with Ag2WO4-doped mesoporous g-C3N4 under visible light

Ag2WO4/g-C3N4 composite photocatalyst was synthesized by polymerization of thiourea and ammonia chloride combined with the deposition-precipitation method, which was applied as an efficient visible light driven photocatalyst for inactivating Escherichia coli (E. coli). The physicochemical properties of these photocatalysts were systematically characterized by various techniques such as SEM, TEM, XRD, FT-IR, BET, UV-vis DRS and PL. The synthesized photocatalysts exhibited outstandingly enhanced photocatalytic disinfection efficiency compared with that of pure g-C3N4 and Ag2WO4 under visible light. Furthermore, the optimal mass ratio of the Ag2WO4 to g-C3N4 was 5 wt%, and a number of live bacteria could be completely inactivated with Ag2WO4(5%)/g-C3N4 (100 mu g/mL) after 90 min under visible light irradiation. The high disinfection efficiency is due to the synergetic effect between g-C3N4 and Ag2WO4, including a good distribution of Ag2WO4 particles on the surface of g-C3N4 and an improved separation rate of photogenerated electron-hole pairs. The enhanced disinfection mechanism was also investigated using photogenerated current densities and electrochemical impedance spectroscopy (EIS). Considering the bulk availability and excellent disinfection activity of Ag2WO4/g-C3N4 composite, it is a promising solar driven photocatalyst for cleaning the microbial contaminated water. (C) 2017 Elsevier B.V. All rights reserved.