Ligand Defect‐Induced Active Sites in Ni‐MOF‐74 for Efficient Photocatalytic CO2 Reduction to CO

Abstract The conversion of CO 2 into valuable carbon‐based products using clean and renewable solar energy has been a significant challenge in photocatalysis. It is of paramount importance to develop efficient photocatalysts for the catalytic conversion of CO 2 using visible light. In this study, the Ni‐MOF‐74 material is successfully modified to achieve a highly porous structure (Ni‐74‐Am) through temperature and solvent modulation. Compared to the original Ni‐MOF‐74, Ni‐74‐Am contains more unsaturated Ni active sites resulting from defects, thereby enhancing the performance of CO 2 photocatalytic conversion. Remarkably, Ni‐74‐Am exhibits outstanding photocatalytic performance, with a CO generation rate of 1380 µmol g −1 h −1 and 94% CO selectivity under visible light, significantly surpassing the majority of MOF‐based photocatalysts reported to date. Furthermore, experimental characterizations reveal that Ni‐74‐Am has significantly higher efficiency of photogenerated electron–hole separation and faster carrier migration rate for photocatalytic CO 2 reduction. This work enriches the design and application of defective MOFs and provides new insights into the design of MOF‐based photocatalysts for renewable energy and environmental sustainability. The findings of this study hold significant promise for developing efficient photocatalysts for CO 2 reduction under visible‐light conditions.