Plant-Based Synthesis of ZnO Nanoparticles using Neem Leaves

This study presents an eco-friendly approach for synthesizing zinc ox- ide nanoparticles (ZnO NPs) using Azadirachta indica (neem) leaf extract as a natural reducing and stabilizing agent. The green synthesis method offers a sustainable alternative to conventional chemical synthesis routes that often involve hazardous substances and high energy consumption. Fresh neem leaves were processed to prepare an aqueous extract, which was then reacted with zinc nitrate hexahydrate, followed by calcination at 400°C for 2 hours. The synthesized nanoparticles were comprehen- sively characterized using UV-visible spectrophotometry, scanning elec- tron microscopy with energy dispersive X-ray analysis (SEM-EDX), and Fourier transform infrared spectroscopy (FTIR). The results confirmed the formation of spherical ZnO nanoparticles with sizes ranging from 20- 40 nm. UV-visible analysis revealed characteristic absorption peaks at 273.0 nm and 360.5 nm, confirming the successful synthesis of ZnO NPs. The antibacterial evaluation demonstrated significant inhibitory effects against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, with inhibition zones of 15 mm and 12 mm, respectively. Additionally, the nanoparticles exhibited excellent photo- catalytic activity, achieving approximately 75% degradation of methylene blue dye under UV irradiation within 120 minutes. This green synthesis approach eliminates the use of toxic chemicals, operates under mild condi- tions, and produces multifunctional nanoparticles suitable for applications in antimicrobial treatments, environmental remediation, and sustainable agriculture. Green synthesis Zinc oxide nanoparticles Neem extract antimicrobial activity Photocatalytic degradation Sustainable nanotechnology.