Highly selective photocatalytic CO2 reduction by metal-N4 dynamically generated from atomically dispersed copper

Solar-driven conversion of CO2 into high-value-added chemicals is considered as one of the effective strategies to address global climate change. However, the sluggish charge separation kinetics and poor product selectivity remain the two major bottlenecks restricting photocatalytic CO2 conversion. Herein, we developed an anatase surface modified atomically dispersed Cu (Cu anchored on N-doped carbon skeleton) photocatalyst (TiO2/ Cu1NC) based on a "reflux + calcination" method for CO2 photoreduction. Under full spectral illumination, the as-synthesized TiO2/Cu1NC displayed a brilliant CO production rate of 2.59 mu mol h-1 (mass of photocatalyst: 5 mg), high selectivity (-98.5%), and excellent durability using [Ru(bpy)3]Cl2 & sdot;6H2O as the photosensitizer and triethanolamine as an electron donor. Experiments and density functionalized theory calculations synergistically confirm that the surface-constructed atomically dispersed Cu1NC active sites can accelerate the separation and transfer of photogenerated charge carriers, optimize CO2 adsorption and activation, reduce the formation energy barrier of the key intermediate *COOH during the CO2RR process, and thus enhance the activity and selectivity of CO2RR. This work provides new insights into the surface engineering of atomically dispersed active sites to improve the activity and CO selectivity of CO2 photoreduction.