Structural, electrochemical and corrosion resistance properties of ZnO/rGO nanocomposite for supercapacitor electrode material

In this work, zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposites have been synthesized by a chemical reduction approach with different concentrations of ZnO. The morphology, structural, optical and electrochemical, and corrosion properties characterizations of the synthesized ZnO/rGO nanocomposite were analysed. From XRD, the crystalline size of rGO was found to be 0.28 nm and the average crystallite size for the ZnO/rGO composite was found to be 36.62–30.56 nm from 5 and 7 wt%. The maximum specific capacitance of 7 wt% of ZnO/rGO was found to be 848 F g^–1 at a scan rate of 10 mV s^–1 with the potential window range of –0.3 to 0.3 in 1 M KCl as the electrolyte, when compared for GO. The cyclic stability of the specific capacitance was tested for 1000 cycles at 5 A g^–1 current density, the result shows good cyclic stability, with a retention rate of 60.7%. The minimum values of corrosion potential (E_corr) and corrosion current (I_corr) are 0.012 V and 2.17 A. The ZnO/rGO nanocomposite demonstrated high specific capacitance and strong supercapacitor capabilities.