Facile fabrication of g-C3N4 QDs/BiVO4 Z-scheme heterojunction towards enhancing photodegradation activity under visible light

In this study, we report a facile and green strategy to produce graphitic carbon nitride quantum dots (g-C3N4 QDs)/BiVO4 Z-scheme nanoheterostructure, which is composed by g-C3N4 QDs assembled on the surface of mesh-like BiVO4 crystals. As compared with pure BiVO4, the g-C3N4 QDs/BiVO4 composite showed significantly enhanced photocatalytic performance towards degradation of rhodamine B (RhB) and Tetracycline (TC) under visible light irradiation, which is attributed to the increased surface area, (increased number of photocatalytically active sites) and the improved efficiency of separation of photogenerated electron-hole pairs through an efficient charge transfer Z-scheme system. The stability and durability of photocatalyst are also discussed in detail. Moreover, the possible enhanced photocatalytic mechanism was put forwarded and explained by the electron spin resonance (ESR) spin-trap technique and active species trapping experiments. The successful implementation of this work will have guiding significance for the preparation of photocatalysts, and provide theoretical basis and experimental guidance for future development of Z-scheme photocatalytic mechanism of the hybrid photocatalysts with better performance. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.