Synergistic degradation of rhodamine B on BiOClxBr1-x sheets by combined photosensitization and photocatalysis under visible light irradiation

BiOClxBr1-x sheets were synthesized by a simple precipitation method. These samples showed good activities in the degradation of rhodamine B (RhB) under visible light irradiation (420 nm < lambda < 800 nm). From a series of characterization techniques, the results showed that the degradation was driven by the photosensitization of RhB and photocatalysis of BiOClxBr1-x. The mechanism of the synergistic degradation processes was explored by comparing the degradation properties of BiOClxBr1-x (Cl : Br = 1 : 1) and BiOBr. The main active species that played important roles in the degradation process were electrons and O-2(center dot-) in the BiOClxBr1-x (Cl : Br = 1 : 1) system, while in the BiOBr system, electrons, O-2(center dot-) and holes were the main active species. Such a heterogeneous synergistic degradation reaction has much significance in revealing the degradation mechanism of organic pollutants in ordinary photocatalysis.