Boosting holes generation and O2 activation by bifunctional NiCoP modified Bi4O5Br2 for efficient photocatalytic aerobic oxidation

The insufficient generation of oxidative active species severely limits the activity of photocatalytic aerobic oxidation for organic pollutants degradation in wastewater. Herein, transition metal phosphides (TMPs) cocatalysts, including Ni2P, Co2P, and NiCoP, were loaded on Bi4O5Br2 nanosheets by a simple liquid assembly method. Among which, 15% NiCoP/Bi4O5Br2 heterojunction exhibits the optimal photocatalytic activity for degrading phenolic pollutants owing to the high concentration of h+ and •O2− active species, and it displays excellent tolerance for the inorganic ions, pH value, water matrix, and outdoor sunlight. The S-scheme charge transfer mechanism was revealed for NiCoP/Bi4O5Br2 heterojunction, which significantly improves the separation efficiency of photogenerated charge carriers and facilitates the accumulation of active h+. Furthermore, NiCoP with high reduction potential and outstanding O2 activation ability is served as the active site for producing •O2−. This work can inspire the further design of bifunctional photocatalysts for efficient photocatalytic aerobic oxidation applications.