Fabrication of heterojunction SnO2/BiVO4 composites having enhanced visible light photocatalystic activity

SnO2/BiVO4 heterojunction composite photocatalysts with various mole ratios have been prepared via a simple hydrothermal method. The structure, composition and optical properties of the SnO2/BiVO4 composites were determined by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface analysis, X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). Photocatalytic activities of the composites were evaluated by studying the degradation of methylene blue (MB) solutions under simulated visible light irradiation (500 W halogen tungsten lamp). The 3:7 mol ratio SnO2/BiVO4 composite exhibited the highest photocatalytic performance, leading to 72% decompositon of MB within 120 min of irradiation.