Atomic Cobalt-Silver Dual-Metal Sites Confined on Carbon Nitride with Synergistic Ag Nanoparticles for Enhanced CO2 Photoreduction

Photocatalyticreduction of CO2 to value-added solarfuels is of great significance to alleviate the severe environmentaland energy crisis. Herein, we report the construction of a synergisticsilver nanoparticle catalyst with adjacent atomic cobalt-silverdual-metal sites on P-doped carbon nitride (Co1Ag(1+n)-PCN) for photocatalytic CO2 reduction.The optimized photocatalyst achieves a high CO formation rate of 46.82 mu mol g(cat) (-1) with 70.1% selectivityin solid-liquid mode without sacrificial agents, which is 2.68and 2.18-fold compared to that of exclusive silver single-atom (Ag-1-CN) and cobalt-silver dual-metal site (Co1Ag1-PCN) photocatalysts, respectively. Theclosely integrated in situ experiments and densityfunctional theory calculations unravel that the electronic metal-supportinteractions (EMSIs) of Ag nanoparticles with adjacent Ag-N2C2 and Co-N-6-P single-atomsites promote the adsorption of CO2* and COOH* intermediatesto form CO and CH4, as well as boost the enrichment andtransfer of photoexcited electrons. Moreover, the atomically disperseddual-metal Co-Ag SA sites serve as the fast-electron-transferchannel while Ag nanoparticles act as the electron acceptor to enrichand separate more photogenerated electrons. This work provides a generalplatform to delicately design high-performance synergistic catalystsfor highly efficient solar energy conversion.