Hierarchically porous nano-sized CuO–NiO hybrid system for supercapacitor applications

Abstract

Binary transition metal oxide nanocomposites have come forth as a propitious candidate in the domain of energy storage systems. In this work, pristine CuO, NiO, and CuO–NiO nanocomposites are prepared using conventional and convenient hydrothermal route. This simple and cost-effective hydrothermal synthesis used do not involve any kind of surfactants or hazardous reaction conditions and the end samples were subjected to structural and morphological characterisations. CuO–NiO composite displays a phase blend of monoclinic CuO and cubic NiO structures. All the prominent peaks of composite in the XRD can be well indexed to CuO and NiO crystal structures and the spectra is devoid of impurity peaks. Surface morphological examination shows the highly porous geometry of CuO–NiO composites with rice-like nanostructure. The fusion of CuO and NiO enhances the mesoporous specific surface area of the nanocomposite in comparison with the pristine CuO and NiO. The composite exhibits a compatible performance as a working electrode in supercapacitors, acquiring a specific capacitance of 622 Fg⁻¹ at a current density of 0.3 Ag⁻¹.