Earth-abundant-metal complexes as photosensitizers in molecular systems for light-driven CO2 reduction

This review highlights the development of earth-abundant-metal complexes as the photosensitizers featuring Cu, Zn, Al, or B in molecular photocatalytic systems for CO2 reduction. [Display omitted] •The progress in homogeneous, molecular photocatalytic systems for CO2 reduction with earth-abundant-metal complexes as the photosensitizers were summarized.•The photophysical and photoredox properties of these earth-abundant-metal dyes were highlighted.•Their issues and corresponding operative strategies in photocatalytic CO2 reduction were discussed in detail. Artificial photosynthesis involving CO2 photoreduction is an appealing strategy for addressing environmental and energy-shortage issues. Exploration of cost-efficient photocatalytic systems for CO2 reduction will substantially contribute to sustainable applications. However, the exploitation of earth-abundant alternatives to the extensively applied precious-metal-based photosensitizers for CO2 reduction remains challenging. In this Review, the key development of earth-abundant-metal complexes as photosensitizers in molecular systems for CO2 photoreduction is emphasized to offer an upcoming blueprint, including an analysis of the problems of these photosensitizers during photocatalytic CO2 reduction and presenting potential solutions to overcome issues commonly found.