The oxygen atom coordination inducing the structure reconstruction of the catalytic site is identified and recognized ambiguously, which is related to accurately declare the mechanism in a dynamic catalytic process. Herein, we demonstrated that the reconstructed catalytic sites would lead to a remarkable performance for photocatalytic CO₂ reduction. At the initial 4-cycles testing, the in-situ formation of CoO_x active sites on the Co (CoP) surface performed an increasing transient activity and selectivity toward CO evolution. The formation of reconstructive Co-O bond and the appearance of intermediate specie CO were simultaneously observed by the pre-operando Raman, revealing the dynamic relationship between catalytic site structure and the photocatalytic properties. Moreover, density functional theory calculations showed that the electronic structure of the reconstructive surface sites could modulate the ability of CO₂ adsorption and CO desorption. The reduced barrier energy for the rate-determining step finally improved the activity and selectivity of CO₂ reduction.

Photosensitized heterogeneous CO₂ reduction (PHCR) has emerged as a promising means to convert CO₂ into valuable chemicals, however, challenged by the relatively low carbonaceous product selectivity caused by the competing hydrogen evolution reaction (HER). Here, we report a PHCR system that couples Ru(bpy)₃²⁺ photosensitizer with {001} faceted LiCoO₂ nanosheets photocatalyst to simultaneously yield 21.2 and 722 μmol·g⁻¹·h⁻¹ of CO, and 4.42 and 108 μmol·g⁻¹·h⁻¹ of CH₄ under the visible light and the simulated sunlight irradiations, respectively, with completely suppressed HER. The experimental and theoretical studies reveal that the favored CO₂ adsorption on the exposed Li sites on {001} faceted LiCoO₂ surface is responsible for the completely suppressed HER.