Non-noble-metallic Ni2P nanoparticles modified OV-BiOBr with boosting photoelectrochemical hydrogen evolution without sacrificial agent

Non-noble-metallic Ni2P modified BiOBr with oxygen vacancy (O-V) was synthesized by solvothermal method to construct novel O-V-BiOBr/Ni2P nanoheterojunction. Compared with O-V-BiOBr, the photoelectrochemical hydrogen evolution of O-V-BiOBr/Ni2P was significantly improved. O-V-BiOBr/Ni2P-2% showed the best hydrogen evolution rate of 455.34 mu mol.cm(-2).h(-1) without sacrificial agent, which was 5.94 times that of O-V-BiOBr and 12.88 times that of pristine BiOBr. It was found that an appropriate amount of Ni2P loading enabled the closely contacted O-V-BiOBr/Ni2P to have an optimal O-V concentration, which realized the rapid electron-hole separation, simultaneously, the successful loading of Ni2P can effectively enhance the light absorption capacity. The formation of Bi-O-P chemical bond and nanoheterojunctions jointly promote electron transfer and inhibit carrier recombination. Density functional theory (DFT) calculations find that the hydrogen adsorption free energy of O-V-BiOBr/Ni2P heterojunction is the lowest in this system. This study will provide some guidance for efficient photoelectrochemical hydrogen evolution without sacrificial agent.