Surface modification of m-BiVO4 with wide band-gap semiconductor BiOCl to largely improve the visible light induced photocatalytic activity

Monoclinic BiVO4 (m-BiVO4) was modified with wide band-gap semiconductor BiOCl to construct novel BiOCl/m-BiVO4 heterojunctions. The as-synthesized samples were systematically characterized by X-ray diffraction (XRD), Fourier-transform infrared spectra (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectrum (EDS) and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of BiOCl/m-BiVO4 were evaluated by measuring the degradation of methyl orange, rhodamine B and acid orange II under visible light (λ > 420 nm). The results showed that BiOCl/m-BiVO4 had excellent photocatalytic performance compared with pure m-BiVO4, BiOCl, P25 and N-TiO2, especially 30% BiOCl/m-BiVO4 exhibited the highest photocatalytic activity. The heterojunctions between BiOCl and m-BiVO4 highly separated the photocarriers and yielded enhanced photocatalytic performance of BiOCl/m-BiVO4.