Fabrication of BiOI/BiVO 4 heterojunction with efficient visible-light-induced photocatalytic activity

Abstract For promoting the separation of electron–hole pairs and enhancing visible light photocatalytic activity, a novel visible-light-active BiOI/BiVO 4 photocatalyst with a p–n heterojunction structure was prepared. The prepared photocatalyst was characterized by X-ray diffraction, transmission electron microscope, scanning electron microscopy, diffuse reflectance spectroscopy, and X-ray photoelectron spectrometer. The photocatalytic activity of the heterojunction was investigated by monitoring the change in methyl orange concentration under visible-light irradiation. The results reveal that the composite exhibited markedly improved efficiency for MO photodegradation in comparison with pure BiVO 4 and BiOI. The degradation rate of BiOI/BiVO 4 heterojunction was found to be 19.5 and 2.1 times higher than that of bare BiVO 4 and BiOI, respectively. The enhanced photocatalytic activity is mainly attributed to the formation of BiOI/BiVO 4 heterojunction that can facilitate the separation and transfer of the photogenerated charge carriers.