Spray deposited amorphous RuO2 for an effective use in electrochemical supercapacitor

The structural, surface morphological and optical properties of sprayed ruthenium oxide thin film were investigated using XRD, SEM and optical absorption measurements. The structural analysis from XRD pattern showed the formation of RuO2 in amorphous phase. The scanning electron micrographs revealed network-like morphology of ruthenium oxide. The optical studies showed a direct band gap of 2.4 eV for ruthenium oxide films. Ruthenium oxide thin film exhibited a cyclic voltammogram indicative high reversibility of a typical capacitive behavior in 0.5 M H2SO4 electrolyte. A specific capacitance of 551 F/g was obtained with ruthenium oxide thin film (electrode) prepared by spray pyrolysis method. The specific capacitances of 551 and 450 F/g at the scan rate of 5 and 125 mV/s, respectively, indicate that the capacitance value varies inversely with scan rate.