Enriched electrochemical performance of copper vanadate loaded reduced graphene oxide for supercapacitor applications

Abstract

In this work, the electrochemical performance of copper vanadate (Cu3V2O8) nanoparticles (NPs) and Cu3V2O8 NPs loaded reduced graphene oxide (Cu3V2O8@rGO) nanocomposites (NCs) were reported. Cu3V2O8 NPs and Cu3V2O8@rGO (0.02 M Cu3V2O8 and 0.01 g of rGO) NCs were prepared by a simple reflux technique, and the prepared NCs were analytically investigated. The monoclinic crystalline structure of the prepared Cu3V2O8 NPs was revealed by the XRD analysis. Presence of plate-like structured Cu3V2O8 NPs and layer-structured rGO in the prepared NCs were observed through HR-TEM images. The electrochemical performance of the prepared NCs was investigated through the fabrication of Cu3V2O8 NPs, and Cu3V2O8@rGO NCs modified working electrode and supercapacitor under 1 M aqueous KOH electrolyte. The cyclic voltammetry result suggested that the pure Cu3V2O8 NPs modified working electrode possessed the specific capacitance value of 538 Fg-1 (at 5 mVs-1), and this value was further enhanced to 1341 Fg-1 by the addition of rGO. The maximum specific capacitance values calculated from GCD analysis were found to be 13.2 Fg-1 (at 0.1 Ag-1) for Cu3V2O8 NPs and 1305 Fg-1 (at 1.5 Ag-1) for Cu3V2O8@rGO NCs, based electrodes. The energy and power density values of the fabricated device using Cu3V2O8 NPs were found to be 2.067 W h kg1 and 403.8 W kg-1, respectively. Whereas, Cu3V2O8@rGO NCs-based device possessed 7.642 W h kg-1 and 90 W kg-1 of superior energy and power densities, respectively. The cyclic test result confirmed that the Cu3V2O8@rGO NCs-based device possessed the superior specific capacitance retention of 74% at the end of 2000 cycles, whereas, Cu3V2O8 NPs-based device exhibited only 69.5% of cyclic retention. The electrochemical results suggested that the inclusion of rGO in prepared copper vanadate nanoparticles induced the battery-like behavior. The proposed NCs can be utilized as the supercapacitor and/or battery electrodes.