Constructing robust Z-type BiOBr/Br-doped g-C3N4 heterojunctions for visible light-assisted photocatalytic decontamination of norfloxacin

Abstract

In order to remediate the environment in a green way, the development of new and effective photocatalytic heterojunctions has received great attention from researchers in recent years. Herein, we assembled BiOBr-decorated Br-doped g-C3N4 (BiOBr/BrCN) hybrid heterojunctions in different percentages (BiOBr content = 5–30 wt%) to achieve effective photocatalytic heterojunctions for visible-light-prompted degradation of antibiotic norfloxacin (NOR), in which reducing the photocarriers recombination rate. Obviously, BiOBr/BrCN composites endorsed greater photodecomposition performance of NOR under visible-light illumination. The 10 wt%BiOBr/BrCN photocatalyst decomposed 95.5 % of NOR in 1.5 h, which are approximately 2.5 and 1.7 times of enhancement compared with BrCN and BiOBr, respectively. The enlarged response to visible-light and the efficient separation of photo-induced carriers in the developed Z-system heterojunction between BiOBr and BrCN were behind the boosted photocatalytic activity. Besides, the trapping experiments demonstrated that both •O2− and h+ species take significant roles in the degradation of NOR antibiotic, which supports the proposed mechanism. In addition, the degradation efficiency displays an insignificant decrease after the fifth cycle, indicating that the synthesized BiOBr/BrCN photocatalyst system has a great stability for the practical applications.