Comparative Study of Green and Chemical Synthesis of Metal Oxide Nanoparticles: Structural, Optical, and Catalytic Performance

Green synthesis of metal oxide nanoparticles presents an environmentally sustainable approach compared to traditional chemical routes. In this study, zinc oxide (ZnO) nanoparticles were synthesized via two distinct methods: a green route using Azadirachta indica (neem) leaf extract and a conventional chemical method using zinc acetate and sodium hydroxide. The synthesized nanoparticles were characterized using UV-Vis spectroscopy, FTIR, XRD, SEM/TEM, and DLS techniques. Structural and morphological parameters such as crystallinity, particle size distribution, and surface morphology were analyzed and compared. The green-synthesized ZnO nanoparticles exhibited improved colloidal stability and biocompatibility, while the chemically synthesized ones showed slightly higher crystallinity. Electrochemical sensing studies demonstrated that both types of ZnO nanoparticles could effectively detect analytes, with green-synthesized ZnO showing enhanced electrocatalytic response due to surface-active phytochemical residues. This comparative study highlights the significance of synthesis routes in tailoring the physicochemical and catalytic properties of ZnO nanoparticles for sensor applications.