Engineering structural tunability in MOF-based photocatalysts for efficient CO₂ photoreduction

Metal–organic frameworks (MOFs) offer an exceptional platform for photocatalytic CO₂ reduction (CO₂RR) because metal nodes, organic linkers, defects and pore microenvironments can be engineered to integrate CO₂ capture and light-driven redox chemistry. Yet, the intrinsic trade-offs of many pristine MOFs, limited conductivity, short carrier diffusion lengths, and framework instability under operating conditions often cap activity and selectivity. This review summarizes recent advances in MOF-based photocatalysts, focusing on the integration of MOFs with semiconductors, metal cocatalysts and plasmonic components to optimize band alignment, facilitate interfacial charge transfer and construct efficient catalytic microenvironments. Progress is discussed by major C₁ products (CO, CH₄, CH₃OH and HCOOH), with emphasis on how node/linker electronics, defect chemistry, pore polarity and heterointerfaces govern CO₂ activation, intermediate stabilization and product-determining pathways. We critically examine the correlation between enhanced CO₂ adsorption and the higher photoreduction rates, and the dominant roles of mass transport and interfacial kinetics. Finally, we summarize emerging AI and machine-learning strategies for accelerating materials discovery and mechanistic understanding, and outline key challenges and opportunities toward scalable, selective and durable MOF-based CO₂ photoconversion.