Photocatalytic carbon dioxide (CO₂) reduction offers an alternative strategy for converting CO₂ into high-value added gaseous fuels, thereby paving the way for the development of clean and renewable energy. Metal-organic frameworks (MOFs), characterized by their highly porous structure, exceptional CO₂ adsorption capacity, and tunable architecture, have emerged as promising candidates for photocatalytic CO₂ reduction. This review systematically examines the recent advancement in MOFs-based photocatalysts for CO₂ reduction to CO. It begins with the overview of the fundamental mechanisms and processes of MOFs towards photocatalytic CO₂ reduction. Subsequently, common strategies for the modulation of MOFs-based photocatalysts are summarized, including metallic site modification, functionalized ligand incorporation, morphological control, defect engineering, and heterostructure construction. Notably, the review analyzes the critical factors contributing to the high selectivity of CO₂ photoreduction to CO from both thermodynamic and kinetic perspectives. The conclusion addresses current challenges and future perspectives in designing highly efficient photocatalysts with abundant active sites, providing valuable insights for their continued development.

The demand for high-performance non-precious-metal electrocatalysts to replace the noble metal-based catalysts for oxygen reduction reaction (ORR) is intensively increasing. Herein, single-atomic copper sites supported on N-doped three-dimensional hierarchically porous carbon catalyst (Cu₁/NC) was prepared by coordination pyrolysis strategy. Remarkably, the Cu₁/NC-900 catalyst not only exhibits excellent ORR performance with a half-wave potential of 0.894 V (vs. RHE) in alkaline media, outperforming those of commercial Pt/C (0.851 V) and Cu nanoparticles anchored on N-doped porous carbon (CuNPs/NC-900), but also demonstrates high stability and methanol tolerance. Moreover, the Cu₁/NC-900 based Zn-air battery exhibits higher power density, rechargeability and cyclic stability than the one based on Pt/C. Both experimental and theoretical investigations demonstrated that the excellent performance of the as-obtained Cu₁/NC-900 could be attributed to the synergistic effect between copper coordinated by three N atoms active sites and the neighbouring carbon defect, resulting in elevated Cu d-band centers of Cu atoms and facilitating intermediate desorption for ORR process. This study may lead towards the development of highly efficient non-noble metal catalysts for applications in electrochemical energy conversion.