Fabrication and characterization of high efficient Z-scheme photocatalyst Bi2MoO6/reduced graphene oxide/BiOBr for the degradation of organic dye and antibiotic under visible-light irradiation

A novel Bi2MoO6/reduced graphene oxide/BiOBr (Bi2MoO6/RGO/BiOBr) composite was successfully synthesized via a facile solvothermal synthesis and precipitation method. The Bi2MoO6/RGO/BiOBr composite was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoelectrochemical measurements. The photocatalytic properties were explored for removal of methylene blue (MB) and norfloxacin (NFX) under visible-light irradiation. The Bi2MoO6/RGO/BiOBr composite exhibits the highest degradation rate compared with Bi2MoO6, BiOBr and Bi2MoO6/BiOBr composite, and that removal ratios of MB and NFX were 96.93% and 78.12%, respectively. A Z-scheme catalytic mechanism suitable for the system was proposed based on the results of UV-vis DRS, free radical trapping experiments and M-S carve analysis, in which RGO as an electronic medium can accelerate electron transfer. It is noteworthy that the close contact interface structure promotes the separation of electrons and holes and improves the photocatalytic performance.