Eco-friendly Synthesis of PVA incorporated with ZnO/CuO nanocomposites materials for electrochemical energy storage and optical evaluation applications

In this article, the PVA-ZnO/CuO nanocomposite was synthesised through the coprecipitation method, unveiling a material with remarkable structural and electrochemical properties. X-ray diffraction (XRD) confirmed the crystalline integrity of ZnO and CuO, with ZnO exhibiting a hexagonal wurtzite phase and CuO displaying a monoclinic structure. The incorporation of PVA introduced a significant amorphous nature, reducing the crystallite size from 51.12 nm to 30.26 nm while enhancing lattice strain and structural distortions. Morphological analysis via SEM and TEM revealed a highly porous architecture with uniformly dispersed nanoparticles below 40 nm, promoting synergistic behaviour and superior charge storage. FTIR identified essential functional groups, while UV-visible spectroscopy demonstrated enhanced charge transfer dynamics, attributed to the PVA matrix. Electrochemical analysis showcased an exceptional specific capacitance of 19.97 F/g, energy density of 2.44 Wh/ kg, and power density of 1.33 kW/kg, coupled with outstanding cyclic stability, indicative of self-activation and structural optimization. Impedance analysis revealed efficient charge transfer (R1: 2.38 Omega) and significant capacitance (CPE0: 2.93 mF), validated by a low fitting error of 2.70%. These results highlight the PVA-ZnO/CuO Nanocomposite's applicability for effective and environmentally friendly supercapacitor applications.