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

Non-noble-metallic Ni 2 P modified BiOBr with oxygen vacancy (O V) was synthesized by solvothermal method to construct novel O V -BiOBr/Ni 2 P nanoheterojunction. Compared with O V -BiOBr, the photoelectrochemical hydrogen evolution of O V -BiOBr/Ni 2 P was significantly improved. O V -BiOBr/Ni 2 P-2% showed the best hydrogen evolution rate of 455.34 μmol · 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 Ni 2 P loading enabled the closely contacted O V -BiOBr/Ni 2 P to have an optimal O V concentration, which realized the rapid electron-hole separation, simultaneously, the successful loading of Ni 2 P 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/Ni 2 P heterojunction is the lowest in this system. This study will provide some guidance for efficient photoelectrochemical hydrogen evolution without sacrificial agent. [Display omitted] • Concentration of oxygen vacancy can be regulated by Ni 2 P content in O V -BiOBr/Ni 2 P. • Bi-O-P chemical bond and O V -BiOBr/Ni 2 P heterojunction promote electron transfer. • O V -BiOBr/Ni 2 P displays boosting PEC hydrogen evolution without sacrificial agent. [ABSTRACT FROM AUTHOR]