One-pot synthesis, characterization, and enhanced photocatalytic activity of a BiOBr-graphene composite

Herein, a chemically bonded BiOBr-graphene composite (BiOBr-RG) was prepared through a facile in situ solvothermal method in the presence of graphene oxide. Graphene oxide could be easily reduced to graphene under solvothermal conditions, and simultaneously BiOBr nanoplates with pure tetragonal phase were grown uniformly on the graphene surface. The structure and photoelectrochemical properties of the resulting materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and impedance and photocurrent action measurements. The combination of BiOBr and graphene introduces some properties of graphene into the photocatalysis reaction, such as excellent conductivity, adsorptivity, and controllability. A remarkable threefold enhancement in the degradation of rhodamine B (RhB) was observed with as-prepared BiOBr-RG as compared with pure BiOBr under visible light (λ>420 nm). The enhanced photocatalytic activity could be attributed to the great adsorptivity of dyes, the extended photoresponse range, the negative shift in the Fermi level of BiOBr-RG, and the high migration efficiency of photoinduced electrons, which may effectively suppress the charge recombination.