Green synthesis and surface functionalization of silver nanoparticles using phyllanthus emblica fruit extract

Abstract In this work, silver nanoparticles (AgNPs) were successfully synthesized via an eco-friendly green route using Phyllanthus emblica fruit extract, which acts as both a reducing and stabilizing agent. The formation and surface characteristics of the nanoparticles were systematically investigated at two precursor concentrations (0.1 M and 0.2 M). UV–Visible spectroscopy revealed characteristic surface plasmon resonance (SPR) peaks at 444 nm and 896 nm, confirming nanoparticle formation and indicating concentration-dependent optical behavior. Fourier transform infrared (FTIR) analysis identified prominent bands around 1384 cm⁻¹, attributed to C–O stretching vibrations of alcohols, carboxylic acids, esters, and ethers, suggesting the involvement of biomolecules in surface capping and stabilization. X-ray diffraction (XRD) patterns exhibited distinct diffraction peaks at 38°, 44°, 64°, and 77°, corresponding to the face-centered cubic crystalline structure of silver, thereby confirming phase purity. Scanning electron microscopy (SEM) images revealed predominantly spherical nanoparticles with an average size of approximately 200 nm. Photoluminescence (PL) studies showed emission peaks at 360 nm, 410 nm, and 520 nm, which are associated with electronic transitions involving surface states and defect-mediated recombination processes. The results highlight the crucial role of plant-derived biomolecules in tailoring the surface chemistry, optical response, and structural properties of AgNPs, demonstrating their potential for applications in biomedical and optoelectronic fields.