Conserved crystal phase and morphology: Electrochemical supremacy of copper (Cu) and iron (Fe) dual-doped nickel oxide and its supercapacitor applications

Abstract A systematic investigation on the structural, magnetic, and electrochemical properties of pristine and Cu-Fe dual-doped nickel oxide (NiO) nanoparticles (NPs) was effectively produced by a chemical precipitation technique and calcinated at 800 °C. XRD studies has confirmed the phase purity of the materials and the crystallographic parameters were found out and reported. The morphological phenonmenon of the materials was studied by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Energy-dispersive X-ray spectroscopy (EDX) confirmed the existence of elements Ni, Cu, Fe, and O and ruled out any unwanted assay. Fourier transform infrared spectrometer (FT-IR) showed the presence of the peak at 490 cm−1 which confirmed the formation of Ni–O. The optical studies show an increase in the energy band gap from 3.01 eV to 3.32 eV. Magnetic characterization reveals a conversion of NiO from weak ferromagnetic to ferromagnetic behavior on the incorporation of Cu-Fe within NiO lattice. The electrochemical performance verified the pseudocapacitive nature of the materials and the highest specific capacitance (1066.75F/g) for Ni0.9Cu0.04Fe0.06O was recorded, which is higher than values previously reported NiO materials. Ni0.9Cu0.04Fe0.06O GCD findings at 0.1 A/g scan rate demonstrated good charging-discharging capabilities. The structural, magnetic, and electrochemical characteristics of pristine and Cu-Fe dual-doped NiO NPs are improved in this effort for use in spintronics and supercapacitors.