Ru Single Atom Dispersed Cu Nanoparticle with Dual Sites Enables Outstanding Photocatalytic CO₂ Reduction

Cu-based catalysts are promising candidates for CO₂ reduction owing to the favorable energetics of Cu sites for CO₂ adsorption and transformation. However, CO₂ 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 Bi₄Ti₃O₁₂ exhibits exceptional activity and selectivity for CO₂ 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 CO₂ molecules. Importantly, the Ru-Cu dual sites exhibit extremely strong CO₂ adsorption ability, and the Gibbs free energy of the rate-determining step (*CO₂ to *COOH) has been significantly reduced, synergistically enhancing the entire CO₂ conversion process. The optimal BTOCu₂Ru_0.5 photocatalyst manifests a high performance for selective reduction of CO₂ 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 CO₂.