Synthesis and characterization of nickel oxide/cobalt oxide nanocomposite for effective degradation of methylene blue and their comparative electrochemical study as electrode material for supercapacitor application

In this paper, we have synthesized a nanocomposite of nickel oxide (NiO) and cobalt oxide (Co3O4) using L-ascorbic acid which is named A(NC). Herein, A stands for L-ascorbic acid, N stands for nickel oxide (NiO), and C stands for cobalt oxide (Co3O4). Where L-ascorbic acid has been used as stabilizing agent/capping agent. Herein, a simple two steps wet-chemical method has been used for the synthesis of the nanocomposite A(NC). This synthesized nanocomposite has been characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). A comparative electrochemical study has been done using cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) techniques for supercapacitor performance. This study has been performed with a three-electrode system using 1 M Na2SO4 as a supporting electrolyte. Herein, a glassy carbon electrode (GCE) as a working electrode, Ag/AgCl as a reference electrode and Pt electrode as a counter electrode have been used in the elec-trochemical analysis. The CV curves have been recorded at different scan rates of 5 mV/s, 10 mV/s, 15 mV/s, 20 mV/s, 40 mV/s, 80 mV/s, and 100 mV/s respectively. The value of specific capacitance has been calculated 2.1472 F/g at 5 mV/s and energy density at 0.1074 Wh/kg using the CV curves. Whereas, specific capacitance and energy density have been determined 0.6833 F/g and 0.0342 Wh/kg respectively using the GCD method. Also, the photocatalytic degradation behavior of the synthesized nanocomposite A(NC) has been investigated against methylene blue (MB) dye. Herein, 89.88% MB dye has been degraded with synthesized nanocomposite A(NC) within 360 min in the presence of sunlight. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this paper, a nanocomposite of nickel oxide and cobalt oxide was synthesized using L-ascorbic acid as a stabilizing agent. The nanocomposite was characterized and its electrochemical performance for supercapacitors was studied. The comparative study between cyclic voltammetry and galvanostatic charge/discharge techniques was conducted, and the photocatalytic degradation behavior of the nanocomposite was investigated.