Metal-Organic Frameworks for Photocatalytic CO₂ Reduction: Progress and Prospects

Global energy scarcity and environmental crises driven by fossil fuel dependence necessitate innovative carbon-negative technologies. Artificial photosynthetic systems (APS), particularly metal-organic frameworks (MOFs), have emerged as transformative platforms for photocatalytic CO₂ reduction reactions (CO₂RR), offering dual solutions for sustainable fuel production and CO₂ utilization. MOFs' crystalline porous architectures enable molecular-level integration of band structure engineering, spatially ordered active sites, hierarchical CO₂ adsorption, and optimized charge transport, surpassing conventional semiconductor catalysts in selectivity, efficiency, and stability. This Review examines recent strategies to enhance the photocatalytic performance of MOFs by engineering metal nodes, organic linkers, and pore microenvironments, with a focus on three pillars: photon harvesting, charge transfer dynamics, and selective multicarbon (C2+) product generation. As research pivots toward C2+ fuels, we analyze structural design principles governing C-C coupling, emphasizing synergistic metal-linker interactions, pore confinement effects, and catalytic site precision. Key advancements in light absorption via linker functionalization, charge separation through conductive pathways, and tailored active sites for kinetic control are critically evaluated. By establishing structure-property relationships, this work highlights the unique capacity of MOFs to bridge atomic-scale tunability with macroscopic catalytic efficacy, providing a roadmap for developing high-performance photocatalysts that convert CO₂ into value-added hydrocarbons. The insights presented aim to accelerate the transition from incremental CO₂ mitigation to scalable, solar-driven, carbon-negative energy systems.