Atomic Cobalt–Silver Dual-Metal Sites Confined on Carbon Nitride with Synergistic Ag Nanoparticles for Enhanced CO<sub>2</sub> Photoreduction
Aixin Deng, En Zhao, Qi Li, Yue Sun, Yazi Liu, Shaogui Yang, Huan He, Yan Xu, Wei Zhao, Haiou Song, Zhe Xu, Zupeng Chen
Abstract
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.