Preparation and properties of BiVO₄/TiO₂-graphene composite photocatalysts with wide spectra

BiVO₄/TiO₂-graphene(BiVO₄/TiO₂-GR) photocatalysts were prepared by a facile solvothermal method. The composite photocatalysts were characterized by X-ray diffraction,transmission electron microscopy,UV-Vis diffuse reflectance spectrometry,and photoluminescence spectrometry. The photocatalytic activity was evaluated by degradation of methylene blue(MB)under simulated sunlight irradiation. It is found that the composite photocatalysts have a strong absorption peak in the 530-800 nm range of visible light. The introduction of graphene not only enlarges the absorption range of visible light,but also makes BiVO₄ and TiO₂ particles disperse uniformly in graphene sheets,and can capture and transfer the photogenerated charges,leading to an efficient improvement in photocatalytic activity.