Heterojunction of BiPO4/BiOBr photocatalysts for Rhodamine B dye degradation under visible LED light irradiation

BiOBr synthesized by alcoholysis precipitation is used in the preparation of BiPO4/BiOBr composites by adding H3PO4. Pristine BiOBr and a series of BiPO4/BiOBr composites have been successfully synthesized using an entirely room‐temperature production process. X‐ray powder diffraction, scanning electron microscopy, High‐resolution transmission electron microscopy, X‐ray photoelectron spectroscopy, UV–vis absorption spectroscopy were used to investigated the bulk structure, surface morphology, element composition and optical properties of the samples. The degradation effect of different proportions of BiPO4/BiOBr composites, BiOBr and BiPO4 on Rhodamine B (RhB) was evaluated under visible LED light irradiation. Compared to pure BiOBr and BiPO4, the as‐synthesized BiPO4/BiOBr composites showed enhanced performance, with 30% BiPO4/BiOBr composite showing the best performance, as it could degrade 95.66% of RhB (100 ml, 15 mg/L) within 120 min. The enhanced photocatalytic activity of BiPO4/BiOBr was attributed to the heterojunction formation between BiOBr and BiPO4 and efficient charge separation. Under the irradiation of visible light, the energy level difference between BiPO4 and BiOBr cause delectrons to flow from one phase to another. Thus, the recombination of photogenerated electron–hole pairs of BiPO4/BiOBr composites were substantially inhibited.