Mechanisms and Structural Regulation of Metal–Organic Framework Materials for Photocatalytic CO 2 Reduction

Photocatalytic CO 2 reduction can convert CO 2 into high-value chemicals and fuels such as CO, HCOOH, CH 3 OH, and CH 4 by utilizing solar energy, representing an important pathway for carbon resource utilization. Metal-organic frameworks (MOFs), with their tunable metal nodes, organic linkers, and regular pore structures, exhibit unique advantages in CO 2 enrichment, light absorption, charge transport, and stabilization of key intermediates. This review focuses on the mechanisms and structural regulation of MOFs for photocatalytic CO 2 reduction. It first introduces the fundamental processes of photogenerated carrier generation and migration, CO 2 adsorption and activation, proton-coupled electron transfer, and product formation. It then summarizes representative MOF systems based on Zr, Fe, and Ti, as well as the performance characteristics of composites with metal nanoparticles, molecular catalysts, and semiconductors. On this basis, it further analyzes the influence mechanisms of metal-node regulation, linker functionalization, defect engineering, pore-microenvironment modulation, and heterointerface construction on light absorption, charge separation, intermediate adsorption, and product selectivity. Existing studies indicate that the photocatalytic performance of MOFs depends on the synergistic matching of their electronic structure, active sites, and local reaction microenvironment. Future efforts should address challenges including photogenerated charge recombination, structural stability, and selectivity in multi-electron reactions, while combining in situ characterization and theoretical calculations to deepen the understanding of real active sites and reaction pathways, thereby providing a theoretical basis for the rational design of efficient and stable MOF photocatalysts and CO 2 resource utilization.