Hydrothermal Synthesis of RuO2??xH2O/Graphene Hybrid Nanocomposite for Supercapacitor Application

Herein we report a facile approach for synthesis of well dispersed hydrated ruthenium oxide nanoparticles onto the surface of hydrogen exfoliated graphene (HEG) sheets via hydrothermal synthesis route. The as prepared hybrid nanocomposite (RuO₂·xH₂O/HEG) was characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). A symmetrical supercapacitor was fabricated and the electrochemical performance of this model supercapacitor cell was investigated by cyclic voltammetry (CV), chronopotentiometry (CP) and impedance spectroscopy (EIS) in 1.0 M H₂SO₄ solution. The hybrid nanocomposite shows a maximum specific capacitance of 154 F/g and energy density of about llWh/kg at a specific discharge current of 1 A/g (20 wt% Ru loading). The composite also shows a maximum power density of 5 kW/kg and coulombic efficiency of 97% for a specific discharge current of 10 A/g.