Iron oxide- and copper oxide-decorated chemically reduced graphene oxide composite as a novel electrode for hybrid supercapacitors

Abstract

In this study, iron oxide- and copper oxide-decorated reduced graphene oxide has been synthesized via a simple wet chemical oxidation-reduction method. The effectiveness of the aforementioned composite as an electrode for supercapacitors (SCs) has been explored via cyclic voltammetry. Raman spectroscopic measurement shows the appearance of a 2D band at 2670 cm-1 and fitting of the 2D band with multiple Lorentzian functions highlights the formation of a few layers of graphenes. Reduced graphene oxide (RGO) formation and the presence of iron and copper oxides on the RGO surface were evident from both X-ray diffraction and energy dispersive spectroscopy results. The thermogravimetric analysis of the synthesized nanocomposite demonstrated superior thermal stability compared to graphene oxide (GO) with almost 60% retention of initial weight after 500 °C. Both the Brunauer-Emmett-Teller test and scanning electron microscopy images established the formation of pores. Average pore diameters of RGO and nanocomposite were observed to be 1.76 and 1.32 nm, respectively. The as-developed nanocomposite exhibited an admirable specific capacitance (Csp) of 626 F/g at a current density of 1.0 A/g. The bimetallic composite demonstrated an excellent energy density of 86.94 Wh/kg.