Recent advances in MOF-based single-atom photocatalysts for CO₂ to solar fuel conversion under sunlight irradiation

Solar-driven photocatalytic CO₂ conversion offers a sustainable route to address energy demand and carbon emissions. Metal-organic frameworks (MOFs) have emerged as promising photocatalyst platforms due to their tunable structures and well-defined coordination environments, while covalent organic frameworks (COFs) also offer ordered porosity and tunable electronic structures that support single-atom catalysts. Incorporation of single-atom active sites in MOFs and COFs further enhances site utilization, charge separation, and photocatalytic performance. This review offers a unified perspective on MOF-based single-atom photocatalysts for CO₂ conversion by focusing on the synergistic interaction between atomically dispersed metal sites and MOFs. Unlike previous reports, it systematically compares different single-atom incorporation strategies and directly correlates atomic coordination environments with photocatalytic performance. By linking the structure, coordination, and activity, this work provides clear design guidelines for developing efficient and durable solar-driven CO₂ reduction systems.