UV‐Light‐Induced Surface Reconstruction of Cubic Cu2O Promotes CO2 Electroreduction to C2 Products

Carbon dioxide electroreduction has been considered as one of the most appealing ways to reducing the CO2 emission but raising the selectivity of high-value added products like C2+ still faces great challenge. Herein, we report a convenient way to modify the cubic Cu2 O particles through UV-light irradiation induced reduction in a solution containing H2 O2 and i-propanol. The plane surface of Cu2 O was reconstructed to roughness shell composed of abandant grain boundaries, in which the ration of Cu+ /Cu0 can be easily regulated by controlling the irradiation time. At the same time, the increasing electrochemical active surface area facilitated the exposure of active sites. Combining of above factors, the Faradaic efficiency of C2 (ethylene and ethanol) from CO2 electroreduction was greatly increased to 62.56% with a high partial current density of 145 mA cm-2 . Our work put forward a facile method for the fine control of the surface structure of cuprous oxide and a novel platform to elucidate the synergistic effects of Cu+ /Cu0 on CO2 electroreduction.