Engineering of CoO electrode via Ni and Cu-doping for supercapacitor application.

Although cobalt oxides show great promise as supercapacitor electrode materials, their slow kinetics and low conductivity make them unsuitable for widespread application. We developed Ni and Cu-doped CoO nanoparticles (NPs) via a simple chemical co-precipitation method without the aid of a surfactant. The samples were analyzed for their composition, function group, band gap, structure/morphology, thermal property, surface area and electrochemical property using X-ray diffraction (XRD), ICP-OES, Fourier transform infrared (FTIR) spectroscopy, Ultraviolet-visible (UV-Vis), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA) and/or Differential thermal analysis (DTA), Brunauer-Emmett-Teller (BET), and Impedance Spectroscopy (EIS), Cyclic voltammetry (CV), respectively. Notably, for the prepared sample, the addition of Cu to CoO NPs results in a 11.5-fold increase in specific surface area (573.78 m g) and a decrease in charge transfer resistance. As a result, the Ni doped CoO electrode exhibits a high specific capacitance of 749 F g, 1.75 times greater than the pristine CoO electrode's 426 F g. The electrode's enhanced surface area and electronic conductivity are credited with the significant improvement in electrochemical performance. The produced Ni doped CoO electrode has the potential to be employed in supercapacitor systems, as the obtained findings amply demonstrated.