Rational design of metal–organic framework based photocatalysts correlated with specific additives for driving gas–liquid-solid CO2 reduction

Abstract

Crystalline porous materials such as metal–organic frameworks (MOFs) have already been applied extensively to photocatalytic CO₂ conversion because of the semiconductor-like property, high specific surface area, and tunable structure. Most of MOFs have existing problems of self-decomposition during gas–solid photocatalytic CO₂ reduction, making them more applicable to a gas–liquid-solid reaction system due to the advantages of room-temperature environment and uniform dispersion of catalysts. However, the review specifically focusing on the progress of gas–liquid-solid photocatalysis over MOF-based materials is relatively scarce so far. Unlike the reaction of CO₂ gas with H₂O vapour in gas–solid mode, the gas–liquid-solid reaction system consists of diverse additives such as photosensitizers and sacrificial agents, which strongly depend on the structural design of photocatalysts. This review classifies the structure of MOF-based materials that correlated with their requirements of specific additives for driving CO₂ reduction. Specifically, we review the recent advances from the requirements of photosensitizers and sacrificial additives to the green overall photosynthesis (just using H₂O as the electron donor). The corresponding strategies for the structural design of MOFs from the aspects of crystal structure, building blocks, photosensitizer units are discussed to clarify the structure–activity relationship. Finally, the challenges and prospects are proposed to develop green and effective MOF-based photocatalysts for CO₂ utilization.