Ru Single Atom Dispersed Cu Nanoparticle with Dual Sites Enables Outstanding Photocatalytic CO 2 Reduction.

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