Plant-Mediated Synthesis of Copper Nanoparticles Using Citrus sinensis Peel Extract and Their Structural Characterization

Nanotechnology has emerged as a rapidly advancing interdisciplinary field with extensive applications in medicine, catalysis, electronics, environmental remediation, agriculture, and material science. Among various metallic nanoparticles, copper nanoparticles (CuNPs) have attracted considerable attention because of their excellent electrical conductivity, catalytic efficiency, antimicrobial activity, optical properties, and cost-effectiveness compared to noble metal nanoparticles. Conventional methods used for the synthesis of copper nanoparticles commonly involve toxic chemicals, hazardous reducing agents, expensive equipment, and high energy consumption, which create environmental and health-related concerns. The present study focuses on the green synthesis of copper nanoparticles using Citrus sinensis (orange) peel extract as a natural reducing and stabilizing agent. Orange peel, generally discarded as agricultural waste, contains several bioactive phytochemicals such as flavonoids, phenolic compounds, ascorbic acid, limonene, terpenoids, and pectin that possess strong antioxidant and reducing capabilities. These phytochemicals facilitate the reduction of copper ions into stable copper nanoparticles. The synthesis process was confirmed by a visible color change in the reaction mixture due to surface plasmon resonance. The synthesized nanoparticles were characterized using UV-Visible spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Characterization studies confirmed the successful formation, crystalline nature, and surface morphology of the synthesized copper nanoparticles. The study highlights an economical, environmentally friendly, and sustainable approach for nanoparticle synthesis using agricultural waste materials, with potential applications in antimicrobial activity, catalysis, environmental treatment, and biomedical research.