Construction of light-sensitive Cu2O/Fe2O3 heterostructures to promote photocatalytic CO2 reduction and photo-assisted charge storage

Abstract

Designing high-performance bifunctional materials for photo-assisted electrochemical charge storage and photocatalysis is challenging due to a hard balance between electroactivity and photo-to-electric efficiency. Herein, copper foam (CF) supported three-dimensional nanoarrays (3D NAs) composed of copper oxide/iron oxide (Cu2O/Fe2O3) heterostructures were constructed as bifunctional materials for photocatalytic CO2 reduction reaction (CO2RR) and photo-assisted supercapacitors. These Cu2O/Fe2O3 3D NAs have demonstrated high electroactivity, and good light adsorption with high photocurrent responses. As a result, the optimized Cu2O/Fe2O3 catalyst can deliver a high methane (CH4) production rate of 38.6 μmol h-1 g-1 with a good cyclic stability for photocatalytic CO2RR. When used for photo-assisted supercapacitors, the optimized Cu2O/Fe2O3 photoelectrode exhibited a maximum photo capacitance of 595 F g-1, delivering a photoenhancement of 17.3% over the capacitance obtained without light (507 F g-1). This work has provided a unique approach to utilize light energy directly to promote electrochemical and photocatalytic properties.