Carbon quantum dot (CQD)-modified Bi3O4Br nanosheets possessing excellent photocatalytic activity under simulated sunlight

Abstract

Abstract Carbon quantum dots (CQDs) modified Bi3O4Br (CQDs/Bi3O4Br) nanosheets were successfully synthesized through a mild hydrothermal method for the first time. Compared with traditional photocatalysts Degussa P25 and g-C3N4, the CQDs/Bi3O4Br composites exhibited better photocatalytic activity in degrading rhodamine B (RhB) under simulated sunlight, and the degradation rate of the composites could be increased by up to 4 times compared with the pure Bi3O4Br. In addition, the CQDs/Bi3O4Br composites also presented higher photocatalytic properties in degrading tetracycline hydrochloride (TC) and bisphenol A (BPA). The activity enhancement was attributed to the heterojunction structure formed by Bi3O4Br and CQDs, which could effectively separate photogenerated carriers. Two major active species, holes (h+) and superoxide radicals (•O2−), were found in the process of photocatalysis. This work may provide a novel method for the environmentally friendly preparation of photocatalysts to remedy freshwater pollution.