Oxygen vacancies synergized with Ni single atoms to enhance efficient photocatalytic hydrogen production in BiOBr

Photocatalysis, as a technology for splitting water to produce hydrogen, has been paid more and more attention. However, the catalyst has fewer active sites and a fast carrier recombination rate resulting in lower activity. In this work, BiOBr-Ni with Ni single atoms and oxygen vacancies was prepared by the microwave - assisted method. The SEM results show that the BiOBr-Ni surface layer is composed of nano-sheets. Electron paramagnetic resonance (EPR) indicates that the prepared BiOBr-Ni contains oxygen vacancies. XRD, XPS and spherical electron microscopy have proved that Ni exists in the form of single atom. In the process of photocatalytic hydrogen production, BiOBr-Ni showed excellent photocatalytic activity. DFT and experimental tests show that the improved photocatalytic hydrogen production is the joint action of oxygen vacancy and Ni single atom, which not only enhances the carrier separation efficiency but also greatly reduces the reaction energy barrier.