Photoelectrochemical reduction of CO2 to alcohols at CuO/CuFeO2 thin film electrode

Abstract

CuFeO2/CuO thin film electrodes are fabricated by electrodeposition method in dimethyl sulfoxide. With the increase of deposition potential and annealing temperature, the peak intensity of both CuO(111) and CuFeO2(101) becomes stronger. The resulted thin film electrodes exhibit high absorbance in visible light range. The photoelectrocatalytic performance of CuFeO2/CuO thin film electrodes for CO2 reduction is examined. At the applied potential between -0.50 to -0.80 V (vs. saturated calomel electrode), CO2 can be reduced to methanol and ethanol. The highest concentration of ethanol occurs at the applied potential of -0.63 V, whereas that of methanol occurs at -0.70 V. There is a strong relationship between Cu/Fe molar ratio on the thin film electrode surface and ethanol concentration, and ethanol concentration increases with the decrease of the Cu/Fe molar ratio of the thin film surface.