Specific capacitance behavior of <scp> Co‐Co ₃ O ₄ </scp> nanocomposite thin films synthesized via different electrodeposition modes

Abstract

High capacitance Co-Co3O4 nanocomposite thin films have been synthesized on nickel foam (NF) using cyclic voltammetry (CV), combination of cyclic voltammetry and potentiostatic (CV PS −1.4 V and CV PS +1 V), and combination of cyclic voltammetry and pulse reverse potential (CV PRP) modes of electrodeposition. X-ray diffraction (XRD) studies reveal the presence of Co and Co3O4 phases for the four electrodeposition modes. The scanning electron microscope (SEM) revealed an interesting morphology correlating the electrochemical and capacitance behavior, while the energy-dispersive X-ray spectroscopy (EDX) spectra confirmed the varying quantities of Co and O in the Co-Co3O4 nanocomposite thin films. The presence of Co-O bonds were also confirmed by the attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra obtained on these films. The capacitance values of Co-Co3O4 composite thin films obtained by CV, CV PS −1.4 V, CV PS +1 V, and CV PRP, respectively, were found to be 1661, 1400, 1866, and 2580 F g−1 at an applied current load of 1 A g−1, while the capacitance retentions after 500 cycles under a high current load of 20 A g−1 for the same were 85.8%, 77.8%, 87.1%, and 90.5%, respectively. The high capacitance and their retention of the electrodeposited Co-Co3O4 nanocomposite thin films show potentials as high-performance supercapacitor electrode.