Engineering of Cu and Ag-doped reduced graphene oxide for supercapacitor electrode applications

Abstract

This article explores the engineering of reduced graphene oxide (rGO) doped with copper (Cu) and silver (Ag) as cutting-edge electrode materials for high-performance supercapacitors. In the first step rGO was synthesized using improved hummers process with KMnO₄ as oxidizing agent and H₂SO₄ and H₃ PO₄ as intercalating agent. Then, we utilized a facile and scalable co-precipitation method to develop Cu and Ag-doped rGO nanomaterials as electrode for supercapacitor applications. The successful doping and even dispersion of metal nanoparticles on the rGO sheets were validated via characterization utilizing Brunauer–Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). In terms of cycling stability and specific capacitance, Cu, and Ag doped rGO composites outperformed then pristine rGO in electrochemical tests such galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV). Hence, the optimized electrochemical investigation showed that, the 0.25 M Cu-rGO and 0.25 M Ag-rGO samples show small resistance and exhibited the higher specific capacitance of 584.2 F/g and 641.1 F/g respectively at scan rate of 5 mV/s. The energy density and power density of the Cu-rGO and Ag-rGO were calculated to be, 2.98 Wh/kg, 14.24 Wh/kg and 518.16 W/kg, 568.37 W/kg respectively. This study demonstrates a viable approach to creating sophisticated rGO-based electrode materials for energy storage devices of the future.