Electronic interaction between transition metal single-atoms and anatase TiO2 boosts CO2 photoreduction with H2O

Abstract

Single-atom catalysts are playing a pivotal-role in understanding atomic-level photocatalytic processes. However, single-atoms are typically non-uniformly distributed on photocatalyst surfaces, hindering the systematic investigation of structure–property correlation at atomic precision. Herein, by combining material design, spectroscopic analyses, and theoretical studies, we investigate the atomic-level CO₂ photoreduction process on TiO₂ photocatalysts with uniformly stabilized transition metal single-atoms. First, the electronic interaction between single Cu atoms and the surrounding TiO₂ affects the reducibility of the TiO₂ surface, leading to spontaneous O vacancy formation near Cu atoms. The coexistence of Cu atoms and O vacancies cooperatively stabilizes CO₂ intermediates on the TiO₂ surface. Second, our approach allows us to control the spatial distribution of uniform single Cu atoms on TiO₂, and demonstrate that neighboring Cu atoms simultaneously engage in the interaction with CO₂ intermediates by controlling the charge localization. Optimized Cu₁/TiO₂ photocatalysts exhibit 66-fold enhancement in CO₂ photoreduction performance compared to the pristine TiO₂.