Boosting photoelectrocatalytic hydrogen evolution of Bi@OV-BiOBr/Cu3P high-low heterojunction with dual-channel charge transfer

Abstract

A high-low heterojunction composite, oxygen vacancies BiOBr induced Bi precipitation Bi@O V -BiOBr/Cu 3 P with Bi-O-P chemical bond, was synthesized using a solvothermal method. Compared to single substance, the carrier lifetime and separation rate of Bi@O V -BiOBr/Cu 3 P were significantly improved. According to theoretical calculations and experimental results, Cu 3 P can be considered as a hole extractor to accelerate the separation of photogenerated carriers. The successful construction of Bi@O V -BiOBr/Cu 3 P high-low heterojunction with Bi metal can not only activate water molecules and reduce the dissociation energy barrier of water, but also separate and retain the highly reductive electrons. Bi metal and Cu 3 P with low valent play a crucial role in dual-channel charge transfer. Bi@O V -BiOBr/Cu 3 P exhibits the highest hydrogen evolution rate up to 723.85 μmol·cm −2 ·h −1 . It also displays excellent photoelectrocatalytic hydrogen production stability. The boosting hydrogen production activity and stability of Bi@O V -BiOBr/Cu 3 P are attributed to the construction of high-low heterojunctions and the dual-channel charge transfer mechanism. • Bi@O V -BiOBr/Cu 3 P high-low heterojunction connected by Bi-O-P bond was firstly prepared. • Bi@O V -BiOBr/Cu 3 P displays superior photoelectrochemical hydrogen evolution activity and stability. • Electron-hole dual-channel charge transfer effect facilitates swift charge separation and transfer.