Synthesis and characterization of Cu²⁺ doped NiO electrode for supercapacitor application

Nanocrystals of Ni_1−xCu_xO have been synthesized by a simple chemical precipitation method. X-ray diffraction studies showed that the samples have pure cubic phase and the average size of the nanocrystals is found to be in the range of 6.52–13.4 nm. The morphology of NiO nanocrystals analyzed by SEM showed a considerable change from nanoparticles to nanorods on doping and confirmed by FE-TEM analysis. The energy dispersive X-ray analysis results showed that the compositions of the elements are relevant as expected from the synthesis. The optical properties of the nanostructures were also investigated by Photoluminescence spectra. The magnetic properties were investigated at room temperature using the vibrating sample magnetometer and the hysteresis loops confirmed the ferromagnetic behavior of NiO on doping due to smaller size effect. The specific capacitance behavior studied by cyclic voltammetry measurements showed higher specific capacitance on lower concentration of doping which made it as promising electrode material for supercapacitor application.