Facile in situ chemical transformation synthesis, boosted charge separation, and increased photocatalytic activity of BiPO4/BiOCl p-n heterojunction photocatalysts under simulated sunlight irradiation

BiPO4/BiOCl p-n heterojunction photocatalysts were successfully prepared by a facile in situ chemical transformation method with the aim of degrading rhodamine B under simulated sunlight. X-ray diffraction, field emission scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, photoluminescence, and electrochemistry tests were used to characterized the structure, morphology, optical properties, and inhibited recombination of photoinduced charges. BiPO4/BiOCl composites exhibited significantly higher photocatalytic activity for the degradation of rhodamine B than pure BiOCl, and the apparent rate constant is 3.18 times higher than that of BiOCl. The significantly increased photocatalytic activity of the BiPO4/BiOCl composites can be ascribed to the formation of a p-n heterojunction, which can effectively boost the separation of photoinduced electron-hole pairs during the photocatalytic process. Additionally, the main active species were investigated and a plausible mechanism is proposed.