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 intermediates as well as the weak adsorption and tough activation of CO₂. Herein, we report a surface modulation strategy via hydroxyl (–OH) modification to tune the surface state of oxygen-rich-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 the 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 other 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.