Ultrasound assisted formation of reduced graphene oxide-copper (II) oxide nanocomposite for energy storage applications

Abstract

The present exploration emphasizes on facile, one-pot sonochemical technique to fabricate reduced graphene oxide-Copper(II)oxide (rGO-CuO) nanocomposite where optimum amounts of CuO and functionalized-graphene phases synergistically establish superior electrochemical signature. Ultrasound assisted reduction of graphene oxide (GO) in presence of Cu(II) ions in ammoniacal medium followed by in-situ deposition of self-assembled CuO on rGO layers gives rise to the resultant rGO-CuO nanocomposite. The as-synthesized sample on spectroscopic, microscopic, surface and thermal analyses revealed stable, nanostructure morphology with large surface area opening the scope for its supercapacitive applications. The electrochemical performances investigated by cyclic voltammetry and chronopotentiometric charging/discharging cycles at a current density of 1Ag−1 in the potential window of −0.3V to +0.8V in 0.5M Na2SO4 aqueous medium, display appreciable specific capacitance (Cs=227Fg−1) of rGO-CuO nanocomposite compared to the reduced graphene oxide (rGO) (136.4Fg−1) and blank-copper oxide (30.1Fg−1) synthesized, and experimented under similar conditions. In aid executed electrochemical impedance spectroscopy for rGO-CuO nanocomposite suggests supercapacitive behavior with better electrical conductivity and ion transport performances assuring it a promising electrode material for future energy storage devices.