Photocatalytic degradation of organic dye over bismuth vanadate-silicon dioxide-graphene oxide nanocomposite under visible light irradiation

A novel bismuth vanadate-silicon dioxide-graphene oxide (BiVO4/SiO2/GO) nanocomposite was synthesized successfully by using hydrothermal method. The as-prepared nanocomposite was characterized by various techniques, including X-ray diffraction (XRD), field emission scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET). The photocatalytic activity of nanoparticles was evaluated by measuring the removal efficiency of methylene blue (MB) in aqueous solution under visible light irradiation. The results indicated that BiVO4, BiVO4/SiO2, and BiVO4/SiO2/GO exhibited the same diffraction peaks of monoclinic scheelite structure due to the higher content of BiVO4 in the nanocomposite system. The BiVO4 and BiVO4/SiO2 were uniformly agglomerated from irregular particles with the different level of aggregation and the size of several micrometers. In the meantime, BiVO4 and SiO2 particles were adhered firmly on the GO sheets in BiVO4/SiO2/GO nanocomposite. The BiVO4/SiO2/GO nanocomposite showed a much higher efficiency than the pure BiVO4 and the BiVO4/SiO2 hybrid material for MB removal efficiency due to the considerably increased specific surface area and pore size by the adhesion of BiVO4 and SiO2 on GO sheets.