Analysis on Microstructural Properties, Morphology and Electrochemical Performance Kinetics of Monoclinic CuO Nanoparticles

Copper oxide (CuO) nanoparticles were thoroughly analyzed to evaluate their structural, morphological, optical and electrochemical properties. X-ray diffraction (XRD) study confirmed the monoclinic phase and high crystallinity of the prepared nanoparticles, with crystallite sizes ranging between 16 - 21 nm. High-resolution scanning electron microscopy (HRSEM) revealed a mixture of porous, rod-like, and sheet-like morphologies, while transmission electron microscopy (TEM) demonstrated the presence of nanoscale particles of dimensions 10 - 20 nm and chain-like aggregations. Raman spectroscopy validated the monoclinic structure, with characteristic Ag and Bg vibrational modes. UV-Vis spectroscopic analysis highlighted a quantum confinement effect, with a blue-shifted absorption peak at 306 nm and a bandgap of approximately 3.8 eV. Electrochemical investigations using Nyquist plots and cyclic voltammetry (CV) revealed excellent pseudo capacitive behavior, with low charge transfer resistance (Rct) and stable redox processes. The electrochemical impedance spectroscopy (EIS) plot indicated effective ion diffusion and good conductivity, making CuO nanoparticles as promising candidates for energy storage applications such as super capacitors and batteries. The rate constant for the irreversible adsorption-controlled electrochemical process was calculated using Laviron plot.