Accelerating Electron‐Transfer Dynamics by TiO2‐Immobilized Reversible Single‐Atom Copper for Enhanced Artificial Photosynthesis of Urea

Abstract Photocatalysis as a sustainable technology is expected to provide a novel sight for the green synthesis of urea directly using N 2 , CO 2 , and H 2 O under mild conditions. However, the fundamental issue of inefficient electron transfer in photocatalysis strongly hinders its feasibility, especially for the above multi‐electron‐demanding urea synthesis. Herein, an effective strategy of accelerating electron‐transfer dynamics is reported by TiO 2 ‐immobilized reversible single‐atom copper (denoted as Cu SA‐TiO 2 ) to enhance the performance for photosynthesis of urea from N 2 , CO 2 , and H 2 O. As revealed by a series of quasi‐in‐situ characterizations (e.g., electron paramagnetic resonance, and wavelength‐resolved and femtosecond time‐resolved spectroscopies), the expedited dynamics behaviors originating from reversible single‐atom copper in as‐designed Cu SA‐TiO 2 (electron extraction rate: over 30 times faster than the reference photocatalysts) allow the assurance of abundant and continual photogenerated electrons for multi‐electron‐demanding co‐photoactivation of N 2 and CO 2 , resulting in considerable rates of urea production. The strategy above for improving the photoelectron‐extraction ability of photocatalysts will offer a high‐efficiency and promising route for artificial urea photosynthesis and other multi‐electron‐demanding photocatalytic reactions.