Green Synthesis of Silver Nanoparticles Using Psidumguajavaleaf Extract

Abstract

In this paper, the green synthesis of silver nanoparticles (AgNPs) using Psidium guajava leaf extract at room temperature. The prepared silver nanoparticles were characterized using UV-Vsible Spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Thermal gravimetric analysis (TGA). The effects of extract concentration, extract pH and contact time on the size and shape of silver nanoparticles are studied. The data revealed that the rate of formation of nanosilver increased significantly in the basic medium and with increasing temperature. TEM studies showed that the particles to be of various shapes and sizes. X-ray diffraction (XRD) study confirmed crystalline nature of the synthesized nanoparticles. FTIR measurement showed that the silver nanoparticles having a coating of the extract compounds indicating a possible role of groups of phenolic compounds that act as a capping and stabilizing agents for the formed silver nanoparticles. Thermo gravimetric analysis (TGA) was carried out to determine the amount of capping phytochemicals on the silver nanoparticles. Supposed mechanism for the formation of silver nanoparticles is discussed.

Biosynthesis of Silver Based Nanoparticles Using Plant Leaves Extracts and Their Antibacterial Activities

“…This confirmed the presence of phytochemicals, such as alkaloids, flavonoids, polyphenols, saponins, and tannins in the aqueous leaf extract of Ziziphus mauritiana Lam. [24][25][26][27][32][33][34][35]. Medium-intense bands of Ag stretching were observed at approximately 500 and 557 cm -1 .…”

“…Generally, metal nanoparticles are manufactured in two ways: bottom-up (fabrication of material from atom to bottom atom) and top-to-bottom (cutting of bulk material to obtain nano-sized particles). AgNPs made from plant leaf extracts are generally stable even after a month and do not undergo any changes [27].…”

“…The prepared samples had a cubic structure, and the average crystallite sizes (D)were 42.6548 nm and 27.89016 nm, respectively. Scherrer's equation [26][27][28] 𝑫 = 𝟎.𝟗𝝀 𝜷𝐜𝐨𝐬𝜽 …………… ( 1) where λ = 0.154 nm, θ is the diffraction angle, and β is the full width at half maximum, which was used to calculate the crystallite size (Table 1).…”