Enhanced asymmetric supercapacitor and oxygen evolution reaction performance by sugarcane molasses-generated Co3O4 nanostructures

A sugarcane molasses, a promising source of polysaccharides, was used in this study in order to modify the size, shape orientation, surface area, and charge transport properties of Co3O4 nanostructures. Several methods have been used to obtain structural information on nanostructures, including powder X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectrometry, and Fourier transform infrared spectroscopy (FTIR). Furthermore, cyclic voltage measurements (CV), linear sweep voltage measurements (LSV), galvanostatic charge-discharge measurements (GCD), and electrochemical impedance measurements (EIS) were performed on Co3O4 nanostructures in conjunction with various electrochemical measurements. The major contribution of this study was focused on the development of an asymmetric supercapacitor using Co3O4 nanostructures. The oxygen evolution reaction (OER) activity of Co3O4 nanostructures was investigated in an aqueous solution containing 1 M KOH, and an asymmetric supercapacitor was tested in an electrolyte containing 3 M KOH. An optimal Co3O4 nanostructure with OER activity has an overpotential of 330 mV at 10 mA cm(-2) and a Tafel slope of 92 mVdec(-1) . The optimized Co3O4 nanostructure demonstrated excellent durability during OER activity for 40 h. Among the three electrode-based supercapacitors, sample 1 had the highest specific capacity with 1070C/g, the highest capacitive retention percentage at 100%, and the highest columbic efficiency at 101%. Thus, ASC devices based on optimized Co3O4 nanostructures exhibit exceptional specific capacities of 301C/g and 6.4 Wh/Kg at 1.5A/g. The retained capacitance was observed to be 99% after 40000 galvanostatic charge-discharge cycles (GCD).