Enhanced photocatalytic degradation of tetracycline hydrochloride over Au-doped BiOBr nanosheets under visible light irradiation

Bismuth(III) oxybromide (BiOBr) is a typical photocatalyst with a unique layered structure. However, the response of BiOBr to visible light is not strong enough for practical application. Moreover, the charge separation efficiency of BiOBr still needs to be improved. In this study, series of Au-doped BiOBr photocatalysts was prepared through a facile one-step hydrothermal method. The as-prepared Au(0.3)-BiOBr nanosheets exhibited an excellent electrochemical performance. The charge separation efficiency of Au(0.3)-BiOBr nanosheets was enhanced by 18.5 times compared with that of BiOBr. The intrinsic photocatalytic activity of Au(0.3)-BiOBr nanosheets in the degradation of tetracycline hydrochloride was approximately twice higher than that of BiOBr under visible light irradiation. In addition, three pathways were identified for the photocatalytic degradation and mineralization of tetracycline hydrochloride, which involve four reactions: hydroxylation, demethylation, ring opening and mineralization. Accordingly, this study proposes a feasible and effective Au-doped BiOBr photocatalyst, and describes a promising strategy for the design and synthesis of high-performance photocatalysts.