Stabilization of COOH* intermediate through hydroxylation engineering for remarkably efficient photocatalytic CO2 reduction

Abstract

The efficiency of CO2 photoreduction is significantly constrained by uncontrollable reaction intermediate as well as the weak adsorption and tough activation of CO2. Herein, we reported a surface modulation strategy, via hydroxyl (-OH) modification to tune the surface state of rich oxygen vacancy SrTiO3 (STO), which could efficiently optimize the structural attributes of STO, facilitating the robust generation of intermediate COOH* and enhancing the surface affinity of catalyst for CO2 adsorption and activation. Therefore, the CO evolution rate of the STO-OH-5 (90 μmol⋅g-1⋅h-1) catalyst is 2.6 times higher than that of the original STO (34 μmol⋅g-1⋅h-1), outperforming most of the reported photocatalysts. This study elucidates the impact of surface modulation on the photocatalytic performance of STO and presents a viable strategy for the development of high-performance nanomaterial photocatalysts for CO2 conversion.