Promotion of electrocatalytic CO2 reduction on Cu2O film by ZnO nanoparticles

Cu 2 O films were prepared using an improved solution immersion method, whereas ZnO/Cu 2 O films were prepared using an electrodeposition method. Then, the pure Cu 2 O film electrodes and ZnO/Cu 2 O film electrodes were used to reduce CO 2 to CH 3 OH. The crystal structure, morphology, particle size, and specific surface area of pure Cu 2 O films prepared under different immersion times and ZnO/Cu 2 O films prepared under different deposition times and Zn 2+ concentrations were analyzed using X-ray diffraction, scanning electron microscopy, and Brunauer–Emmett–Teller analysis. The electrolytic activity of the pure Cu 2 O film electrodes and ZnO/Cu 2 O film electrodes were studied. Under the same reaction conditions, the ZnO/Cu 2 O film electrode with the Zn 2+ concentration of 0.05 M and the deposition time of 30 min had the highest total CH 3 OH yield of 315.656 μmol/cm 2 and the fastest formation rate of 52.609 μmol/(cm 2  h), and its faradaic efficiency was 45%, which was remarkably higher than that of pure Cu 2 O film electrodes under the same reaction conditions. This study highlighted that ZnO nanoparticles had a very good promotion of electrolytic CO 2 reduction on Cu 2 O film.