The role of ZnO nanowires to improve methanol selectivity on Cu2O nanocubes during CO2 electroreduction

Electrochemical reduction of CO 2 enables a flexible and efficient way of converting CO 2 into diverse products. Cu 2 O is regarded as a crucial species for electrocatalytically transforming CO 2 to methanol while facing challenges such as the deactivation of the catalyst and low selectivity of desired products. Therefore, the modification of Cu 2 O and the improvement of its catalytic activity needs to be addressed. Herein, we reported a novel synthesis of Cu 2 O nanocubes (Cu 2 O-cube) using the wet chemical method and demonstrated a Faradaic efficiency of 29.1 % for methanol. We found Cu 2 O (100) facet was responsible and beneficial to improve methanol production . The performance degradation at different potentials due to the deactivation of Cu 2 O-cube were revealed from the changes of surface morphologies by scanning electron microscope (SEM). The electrocatalytic activity of Cu 2 O-cube was further enhanced by embedding Cu 2 O-cube into ZnO nanowires (ZnO@Cu 2 O-cube) through drop-drying, leading to a Faradaic efficiency of 38.9 % towards methanol at − 0.45 V vs. RHE. For parallel comparison, an alternative binding form of ZnO and Cu 2 O was investigated through stacking Cu 2 O film onto ZnO nanowires (ZnO@Cu 2 O-film) through electrodeposition . The results elucidated that the existence of ZnO tended to suppress the production of ethanol and the binding site of ZnO-Cu 2 O could improve the selectivity of methanol.