Physioelectrochemical investigation of the supercapacitive performance of a ternary nanocomposite by common electrochemical methods and fast Fourier transform voltammetry

Abstract

Ternary nanocomposite materials of polyaniline, as supercapacitor electrodes with remarkably high specific capacitance, are electrosynthesized on a glassy carbon electrode (GCE). Scanning electron micrographs clearly revealed the formation of the nanocomposites on the surface of the working electrode. The supercapacitor properties of the composite films are investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), galvanostatic charge/discharge and fast Fourier transform continuous cyclic voltammetry (FFTCCV) technique in an acidic solution. A very high specific capacitance of 303 F g⁻¹ is obtained from PANI in the presence of reduced graphene oxide and Au nanoparticles in an acidic electrolyte. Furthermore, the FFTCCV technique is considered as the most powerful technique in the characterization of new composite materials for supercapacitors. By using this technique, the electrochemical behavior of the system is monitored momentarily. The absolute capacitive charge changes (ΔQ_n) are calculated from the three-dimensional (3D) CVs of the composite electrode at a scan rate of 50 mV s⁻¹ and a computer program algorithm. The present study introduces new nanocomposite materials for electrochemical redox capacitors with advantages that include long life cycling and stability due to the synergistic effects of each component.