Unraveling the Synergistic Catalysis Effect in MOF-Based Photocatalysts.

Metal-organic frameworks (MOFs) have emerged as promising porous crystalline catalysts for solar-to-chemical energy conversion, owing to their customizable structures, large specific surface areas, tunable active sites, and regulatable pore microenvironments. Nevertheless, they still suffer from limitations such as narrow light absorption, rapid charge recombination, insufficient active sites, and poor stability. Synergistic catalysis engineering represents a key strategy to overcome these bottlenecks and enhance the photocatalytic performance of MOF-based photocatalysts. This review systematically summarizes recent advances in synergistic catalytic effects within MOF-based materials, focusing on four core synergistic modes: metal-ligand synergy, bimetallic sites synergy, ligand-ligand synergy, and MOF-based composite synergy. The underlying mechanisms of these synergies are elucidated from the perspectives of light absorption regulation, photogenerated charge separation and migration, band structure engineering, and active site modulation. Meanwhile, their applications in photocatalytic water splitting, selective CO2 reduction to C1 and C2+ products, and organic transformations are overviewed, with an emphasis on elucidating the structure-activity relationship between synergistic configuration and photocatalytic performance. Finally, the challenges and future research directions are also proposed, aiming to provide guidance for the rational design of high-efficiency MOF-based photocatalysts for solar-to-chemical conversion.