Oxygen-Bridged Cu2O/Cu-Al LDH Interface For Efficient Photocatalytic CO2 Reduction

Abstract Photocatalytic reduction of CO2 to high-value-added chemicals is widely recognized as one of the most promising strategies to achieve a closed carbon cycle. In contrast to the traditional heterojunction design principles, this study proposes a paradigm, the "oxygen-bridge electronic relay". The formation mechanism and coordination environment of Cu+-O-Cu2+ oxygen bridges have been systematically studied by in situ spectroscopy and density functional theory calculations. Under visible light irradiation, the CO release rate of Cu-CAL doped at 3:7 with Cu2O and CAL reached 137.45 μmol g−1 h−1, which was 5 times higher than that of the original CAL. After five consecutive cycles of testing, the catalytic activity of Cu-CAL remained at 96.25% of its initial level. It clarifies that the oxygen bridge acts as an "electron transfer station" and plays a critical role in accelerating the photoinduced electron transport process. This study reveals the charge-transfer mechanism of the oxygen bridge and its correlation with the catalytic activity, paving the way for real solar carbon cycling applications.