Ultrastable and Efficient Visible‐light‐driven CO 2 Reduction Triggered by Regenerative Oxygen‐Vacancies in Bi 2 O 2 CO 3 Nanosheets

Herein, we first design a fast low-pressure ultraviolet light irradiation strategy for easily regenerating the nearly equivalent surface vacancies. Taking the defective Bi₂ O₂ CO₃ nanosheets as an example, nearly equal amount of oxygen vacancies can be regenerated under UV light irradiation. Synchrotron-radiation quasi in situ X-ray photoelectron spectra disclose the Bi sites in the O-defective Bi₂ O₂ CO₃ nanosheets can act as the highly active sites, which not only help to activate CO₂ molecules, but also contribute to stabilizing the rate-limiting COOH* intermediate. Also, in situ Fourier transform infrared spectroscopy and in situ mass spectrometry unravel the UV light irradiation contributes to accelerating CO desorption process. As a result, the O-defective Bi₂ O₂ CO₃ nanosheets achieve a stability up to 2640 h over 110 cycling tests and a high evolution rate of 275 μmol g^-1 h^-1 for visible-light-driven CO₂ reduction to CO.