Synthesis and Characterization of Silver Nanoparticles Using Green Plant Extracts

Abstract

Silver nanoparticles (AgNPs) have attracted extensive attention because their optical, catalytic, antimicrobial, and biomedical properties depend strongly on particle size, morphology, crystallinity, and surface chemistry. Conventional chemical routes often use hazardous reducing agents and stabilizers; therefore, plant-mediated green synthesis provides a safer and potentially scalable alternative. This methodology paper proposes an aqueous synthesis of AgNPs using a green plant leaf extract, with Azadirachta indica (neem) used as a model botanical source. Phytochemicals such as polyphenols, flavonoids, terpenoids, sugars, and proteins serve simultaneously as reducing and capping agents. The method uses 1 mM silver nitrate, controlled extract-to-salt ratios, pH, temperature, and reaction time, followed by centrifugation, washing, and drying. Characterization is performed by UV–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM/TEM), and energy-dispersive X-ray spectroscopy (EDX). Representative outcomes expected from this protocol include a brown colloid with a surface-plasmon band near 420–440 nm, predominantly spherical nanosilver in the tens-of-nanometres range, and face-centred-cubic Ag reflections. The method offers a low-cost, environmentally compatible framework suitable for systematic laboratory optimization and subsequent antimicrobial or catalytic evaluation.