Oxygen vacancy–based metal oxides photoanodes in photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is considered as a promising technology for producing clean energy such as hydrogen. The urgent challenge in this field is how to prepare highly efficient electrode materials. The introduction of oxygen vacancies (OVs) into catalytic materials has been confirmed to be an effective strategy toward enhancing the performance of PEC water splitting by both theoretical calculations and experiment results. Herein, the existing strategies for introducing OVs into nanomaterials are discussed in this minireview. In addition, the effect of OVs on PEC water splitting to improve the light absorption efficiency, charges transfer efficiency, and charge injection efficiency was summarized. Finally, we propose several challenges that need to be addressed in the field of PEC water splitting in the future. This minireview could offer some important contributions to the future synthesis of nanomaterials with rich OVs for PEC application. [Display omitted] •Photoelectrochemical (PEC) water splitting is one of the most promising technologies for producing hydrogen.•Presenting the existing strategies for introducing oxygen vacancies into metal oxides.•The effect of oxygen vacancy on photoanodes was summarized.•Providing some perspectives on the challenge for future research in photoelectrochemical water splitting.