GREEN SYNTHESIS OF SILVER NANOPARTICLES USING PSIDUMGUAJAVALEAF EXTRACT

Abstract

In this paper, the green synthesis of silver nanoparticles (AgNPs) usingPsidium guajava leaf extract at room temperature. The prepared silvernanoparticles were characterized using UV-Vsible Spectroscopy, TransmissionElectron Microscopy (TEM), X-ray diffraction (XRD), Fourier transforminfrared (FTIR) and Thermal gravimetric analysis (TGA). The effects of extractconcentration, extract pH and contact time on the size and shape of silvernanoparticles are studied. The data revealed that the rate of formation ofnanosilver increased significantly in the basic medium and with increasingtemperature. TEM studies showed that the particles to be of various shapes andsizes. X-ray diffraction (XRD) study confirmed crystalline nature of thesynthesized nanoparticles. FTIR measurement showed that the silvernanoparticles having a coating of the extract compounds indicating a possiblerole of groups of phenolic compounds that act as a capping and stabilizingagents for the formed silver nanoparticles. Thermo gravimetric analysis (TGA)was carried out to determine the amount of capping phytochemicals on the silvernanoparticles. Supposed mechanism for the formation of silver nanoparticles isdiscussed.Keywords: Green synthesis, Psidium guajava, leaf extract, Ag NPs.