Preparation of Au/BiOBr/Graphene composite and its photocatalytic performance in phenol degradation under visible light

BiOBr, BiOBr/Graphene and Au/BiOBr/Graphene composites were prepared by hydrothermal synthesis and dopamine in-situ reduction method; their morphology, composition, phase structure and optical absorption properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflection spectroscopy (DRS) and photoluminescence (PL) emission spectroscopy. The photocatalytic performance of Au/BiOBr/Graphene in phenol degradation under visible light was investigated. The results indicate that the Au/BiOBr/Graphene composite exhibits enhanced absorption in the visible light region as well as superior photocatalytic activity in the degradation of aqueous phenol, in comparison with BiOBr and BiOBr/Graphene, owing to the enhanced quantum efficiency, narrowed band gap (2.25 eV) and surface plasmon resonance of Au nano particles. Over Au/BiOBr/Graphene composite, the degradation rate of phenol reaches 64% in 180 min under visible light irradiation.