Direct synthesis of RGO/Cu2O composite films on Cu foil for supercapacitors

Abstract Reduced graphene oxide/cuprous oxide (RGO/Cu 2 O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu 2 O and reduction of GO, in which Cu 2 O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu 2 O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry ( CV ), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry (EIS) in 1 M KOH aqueous solution. A specific capacitance of 98.5 F g − 1 at 1 A g − 1 was obtained, which is much higher than that of pure Cu 2 O prepared under the same conditions, due to the presence of RGO.