Manipulated Photocatalytic Air-Concentration CO2 into CH3OH by Dual Hetero-Metal Atom Pair Sites

Carbon dioxide (CO2) reduction encompasses intricate protonation steps, frequently leading to unpredictable products. To achieve target product selectivity, it is essential to strategically manipulate the reaction pathway. Herein, we build Cu−Ag dual hetero-metal atom pair sites for photoreduction of 0.03% CO2 into methanol (CH3OH). In situ Fourier transform infrared spectroscopy is employed to probe the formation of the *CHO group, a critical intermediate during the synthesis of CH3OH, in the CO2 photoreduction on the CuAg/In2O3 nanosheets. Nevertheless, this critical intermediate is not detected under similar conditions on the In2O3 nanosheets. Additionally, theoretical calculations reveal that the energy barrier for the formation of *CHO intermediates (0.31 eV) is lower than that required for the desorption of *CO intermediates to produce carbon monoxide (0.57 eV) on the CuAg/In2O3 nanosheet slab. That suggests a pronounced selectivity toward the production of CH3OH. Consequently, the CuAg/In2O3 nanosheets realize photoreduction of 0.03% CO2 into CH3OH without any sacrificial agent, achieving a formation rate of 3.67 μmol g–1 h−1.