Atomic Cobalt-Silver Dual-Metal Sites Confined on Carbon Nitride with Synergistic Ag Nanoparticles for Enhanced CO 2 Photoreduction.

Photocatalytic reduction of CO 2 to value-added solar fuels is of great significance to alleviate the severe environmental and energy crisis. Herein, we report the construction of a synergistic silver nanoparticle catalyst with adjacent atomic cobalt-silver dual-metal sites on P-doped carbon nitride (Co 1 Ag (1+ n ) -PCN) for photocatalytic CO 2 reduction. The optimized photocatalyst achieves a high CO formation rate of 46.82 μmol g cat -1 with 70.1% selectivity in solid-liquid mode without sacrificial agents, which is 2.68 and 2.18-fold compared to that of exclusive silver single-atom (Ag 1 -CN) and cobalt-silver dual-metal site (Co 1 Ag 1 -PCN) photocatalysts, respectively. The closely integrated in situ experiments and density functional theory calculations unravel that the electronic metal-support interactions (EMSIs) of Ag nanoparticles with adjacent Ag-N 2 C 2 and Co-N 6 -P single-atom sites promote the adsorption of CO 2 * and COOH* intermediates to form CO and CH 4 , as well as boost the enrichment and transfer of photoexcited electrons. Moreover, the atomically dispersed dual-metal Co-Ag SA sites serve as the fast-electron-transfer channel while Ag nanoparticles act as the electron acceptor to enrich and separate more photogenerated electrons. This work provides a general platform to delicately design high-performance synergistic catalysts for highly efficient solar energy conversion.