Perspective on NiCo2O4-based photocatalysts: From fundamentals, modification strategies to applications

Abstract

Semiconductor-mediated photocatalysis holds promise in both clean energy supply and environmental remediation, and is regarded as one of the most ideal approaches to achieve carbon neutrality in the future. Low-cost, visible-light-response, and high-efficiency semiconductor photocatalysts are the key to practical application of photocatalysis. Compared with the binary counterpart Co3O4, the ternary NiCo2O4 has high cation disorder, variable electronic structure, and asymmetry dual metal sites, thus exhibiting great potential in developing high-efficiency visible-light-response photocatalysts. In this review, the fundamental advantages and drawbacks of NiCo2O4 for heterogenous photocatalysis are first introduced in terms of crystal structure, electronic band structure, and surface atom exposure. Modification strategies for NiCo2O4-based photocatalysts are then surveyed and commented in details, including the aspects of morphology regulation, defect engineering, construction of heterojunction, loading cocatalysts, and integration of multiple strategies. Furthermore, the research progress of NiCo2O4-based photocatalysts for water splitting, carbon dioxide reduction, and pollution degradation are summarized. In particular, some research gaps and problems with property modifications and practical applications are highlighted as well in the context, which offers specific directions for future research. Finally, it is concluded by outlining the challenges and opportunities of NiCo2O4-based photocatalysts for solar energy conversion.