Comprehensive characterization and electrochemical performance of Fe-doped Co 3 O 4 nanoparticles for energy storage applications

Abstract

Abstract This study investigates the structural, spectroscopic, and electrochemical properties of Fe-doped cobalt oxide nanoparticles (Fe-doped Co3O4 Nps). X-ray diffraction (XRD) analysis reveals that the Fe-doped samples have a spinel cubic Co3O4 structure with peaks corresponding to (220), (311), (400), (511), and (400) reflection planes. Fourier-transform infrared (FTIR) analysis shows that the major peaks correspond to Co2+ and Co3+ vibrations in the spinel Co3O4 crystal structure, and their positions shift with the increase in Fe doping concentration. X-ray photoelectron spectroscopy (XPS) studies confirm the presence of Co2+ and Co3+ in the Co 2p spectrum and identify Fe3+ and Fe2+ in the Fe 2p spectrum. Scanning electron microscopy (SEM) reveals the surface morphology of the Fe-doped Co3O4 Nps, showing hexagonal/granular structures with varying pore sizes. High-resolution transmission electron microscopy (HR-TEM) analysis confirms the nanocrystalline nature of the Fe-doped Co3O4 Nps. Energy-dispersive X-ray spectroscopy (EDAX) elemental analysis confirms the presence of Co, O, and Fe in the doped samples. Electrochemical studies, including cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests, demonstrate the electrochemical performance of the Fe-doped Co3O4 Nps. The specific capacitance of the samples increases with the increase in Fe doping concentration, indicating improved rate capabilities and ion diffusion. Overall, Fe doping enhances the structural and electrochemical properties of Co3O4 Nps, making them promising materials for various applications.