Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Neem (Azardirachta indica L.) Leaf Extract

Background and Objective: Growing interest in nanotechnology is being shown in the green synthesis of metal nanoparticles using botanical extracts because it doesn’t involve large energy inputs or the creation of extremely hazardous chemical by-products. The present investigation aimed to study the synthesis of zinc oxide nanoparticles synthesized from neem (Azardirachta indica). Materials and Methods: The study was conducted at the Department of Plant Pathology, Annamalai University (2023-2024). Zinc nanoparticles were synthesized using neem leaf extract, confirmed by a color change from green to dark brown. Characterization involved UV-vis spectroscopy for plasmon resonance, FESEM for surface morphology, FTIR for functional group analysis, and XRD for crystalline structure determination using the Debye-Scherrer equation. These techniques confirmed nanoparticle formation and stability. Results: The UV-vis absorption spectra of the synthesized zinc nanoparticles between 200-800 nm. The ZnNPs in the solution have sizes of several nm which ranged between 149.52-231.64 nm with a predominant shape cluster. Whereas, FTIR spectra of neem ZnNPs resulted in sharp absorption peaks at 3412.80, 2428.71, 2331.93, 2026.69, 1384.54, 1271.24, 872.47, 444.24 cm^–1. The average crystalline size for neem ZnNPs was 37.00 nm. Conclusion: The synthesis involved combining neem extract with zinc salt under controlled stirring conditions, resulting in a color change indicating nanoparticle formation.