Ru Single Atom Dispersed\nCu Nanoparticle with Dual\nSites Enables Outstanding Photocatalytic CO<sub>2</sub> Reduction

Cu-based catalysts are promising candidates for CO<sub>2</sub> reduction\nowing to the favorable energetics of Cu sites for CO<sub>2</sub> adsorption\nand transformation. However, CO<sub>2</sub> reduction involving insurmountable\nactivation barriers and various byproducts remains a significant challenge\nto achieve high activity and selectivity. Herein, a photocatalyst\nconstructed with single-Ru-site-on-Cu-nanoparticle on Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12</sub> exhibits exceptional activity and selectivity\nfor CO<sub>2</sub> conversion to CO. The experimental and theoretical\nresults consistently reveal that the Ru–Cu dual sites allow\nthe rapid transfer of photogenerated carriers for closely interacting\nwith CO<sub>2</sub> molecules. Importantly, the Ru–Cu dual\nsites exhibit extremely strong CO<sub>2</sub> adsorption ability,\nand the Gibbs free energy of the rate-determining step (*CO<sub>2</sub> to *COOH) has been significantly reduced, synergistically enhancing\nthe entire CO<sub>2</sub> conversion process. The optimal BTOCu<sub>2</sub>Ru<sub>0.5</sub> photocatalyst manifests a high performance\nfor selective reduction of CO<sub>2</sub> to CO, yielding 10.84 μmol\nover 15 mg of photocatalyst in 4 h (180.67 μmol·g<sup>–1</sup>·h<sup>–1</sup>) under a 300 W Xe lamp without any photosensitizer\nand sacrificial reagent, outperforming all bismuth-based materials\nand being one of the best photocatalysts ever reported under similar\nreaction conditions. This work presents a strategy for the rational\ndesign of multiple metal sites toward efficient photocatalytic reduction\nof CO<sub>2</sub>.