Green-synthesized Zinc–copper–cobalt Oxide Nanoparticles: Structural, Morphological, Optical and Electrochemical Characterization for Photocatalytic and Supercapacitor Applications

Abstract

This study presents green synthesis of Zinc-Copper-Cobalt Oxide (ZCCO) using tulsi leaf extract as natural reducing agent. Nanoparticles were characterized to evaluate morphological, optical, structural, photocatalytic, and electrochemical characteristics. Powder X-ray diffraction (PXRD) analysis confirmed formation of crystalline mixed-metal oxide phase, while microscopic investigations revealed uniformly distributed nanosized particles with a distinct surface morphology. UV–Visible diffuse reflectance studies demonstrated efficient light absorption characteristics, indicating the suitability of the material for photocatalytic applications. Photocatalytic activity of nanoparticles was examined by degradation of organic dye pollutants under ultraviolet irradiation. The synthesized material exhibited remarkable dye degradation efficiency, demonstrating its potential for wastewater treatment applications. Electrochemical properties were further analysed by galvanostatic charge–discharge measurements, cyclic voltammetry, and electrochemical spectroscopy at alkaline electrolyte. The ZCCO nanoparticles displayed enhanced charge-transfer behavior, strong redox activity, and promising energy-storage performance. These findings suggest that, tulsi-mediated zinc-copper-cobalt oxide nanoparticles can serve as an effective multifunctional material for environmental remediation and electrochemical energy-storage technologies, thereby promoting sustainability. Furthermore, galvanostatic charge–discharge analysis confirmed good capacitive characteristics and excellent electrochemical stability, highlighting their suitability for supercapacitor and advanced energy-storage applications.