Synthesis of BiPO4/Bi2S3 Heterojunction with Enhanced Photocatalytic Activity under Visible-Light Irradiation

摘要

BiPO~(4)/Bi~(2)S~(3) photocatalysts were successfully synthesized by a simple two-step hydrothermal process, which involved the initial formation of BiPO~(4) rod and then the attachment of Bi~(2)S~(3) through ion exchange. The as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectra (UV-vis DRS). It was found that BiPO~(4) was regular rods with smooth surfaces. However, BiPO~(4)/Bi~(2)S~(3) heterojunction had a rough surface, which could be attributed to the attachment of Bi~(2)S~(3) on the surface of BiPO~(4) rods. The BiPO~(4)/Bi~(2)S~(3) composite exhibited better photocatalytic performance than that of pure BiPO~(4) and Bi~(2)S~(3) for the degradation of methylene blue (MB) and Rhodamine B (RhB) under visible light. The enhanced photocatalytic performance could be ascribed to synergistic effect of BiPO~(4)/Bi~(2)S~(3) heterojunction, in which the attached Bi~(2)S~(3) nanoparticles could improve visible-light absorption and the BiPO~(4)/Bi~(2)S~(3) heterojunction suppressed the recombination of photogenerated electron-hole pairs. Our work suggested that BiPO~(4)/Bi~(2)S~(3) heterojunction could be a potential photocatalyst under visible light.