Metal–Organic Framework and CdS Quantum Dots Coupled Enzyme Catalytic System Enhanced CO ₂ Reduction and Formate Synthesis

Abstract Developing highly efficient catalysts to reduce and convert CO ₂ holds profound significance in addressing the global energy and environmental crises. In this work, an innovative hybrid photocatalyst is elaborately designed that integrates a metal–organic framework (MOF) and CdS quantum dots (QDs). The coordination and architecture structure of MOF crystals is readily modulated by increasing the number of benzenes in ligands, achieving a high coordination rate of Rh complex close to 100%. This structural optimization creates a hierarchical network featuring abundant exposed active sites and large pore size for fast mass diffusion. More importantly, the integrated CdS QDs refine the electronic state of Rh, further enhancing efficient electron transfer. Coupling with formate dehydrogenase (FDH), this hybrid photocatalyst not only demonstrates exceptional performance in converting CO ₂ into formate but also simultaneously promotes the highly efficient regeneration of key coenzyme nicotinamide adenine dinucleotide phosphate (NADPH), with an outstanding yield of 85.6%. This work provides a straightforward and feasible method for regulating the coordination architecture and electron transfer of hybrid photocatalysts, offering valuable insights for developing highly active and robust catalysts.