CuO/NiO nanocomposite prepared with Saussurea costus extract for super-capacitor energy storage application

This work reports a green synthesis of CuO/NiO nanocomposite with different CuO/NiO ratios. The X-ray diffraction (XRD) confirmed the existence of both CuO and NiO. This was also confirmed by energy dispersive X-ray (EDX). Scanning electron microscopy (SEM) reveals that changing the compositions of the nanocomposites resulted in different surface morphologies with different particle shapes, sizes, and levels of aggregation. Nitrogen adsorption-desorption analysis showed microporous structures with pore size in the range of 1.66-1.75 nm and surface area in the range of 82-513 m2g−1. The supercapacitive activity was examined by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The results display that the 1C3N exhibited the highest capacitive performance of 1072 Fg−1 compared to 760, 716, and 260 Fg−1 for 3C1N, 4 N, and 4 C, respectively. Furthermore, the 1C3N electrode shows a cyclic stability of 72% after 4000 cycles, which makes it a promising candidate for supercapacitive applications.