Metal nanoparticles prepared by using plant extracts as reducing agents: A review

Abstract

The unusual properties of metal nanoparticles make them appropriate for utilization in various areas of optoelectronics, catalysis, pharmaceuticals, etc. They have been synthesized using numerous physical and chemical methods but currently the approach of green synthesis is catching worldwide attention due to being eco-friendlier and economic. In the present study we have prepared Silver (Ag), Iron (Fe), Palladium (Pd) and Zinc (Zn) nanoparticles via the leaves of plants (<em>Melia azedarach, Urtica dioica and Ziziphus jujuba</em>)<em>. </em>The synthesized nanoparticles were characterized using UV-VIS spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Heat treatment was provided to the as synthesized Pd nanoparticles at different temperatures. The XRD pattern of Ag nanoparticles displayed formation of face-centered cubic (FCC) structure and those of Zn nanoparticles and as synthesized Pd nanoparticles showed low crystalline nature. Also, presence of oxides of metals along with the metals was found in the Fe, Zn samples, although Fe nanoparticles displayed crystalline behavior. Significant improvement in crystallinity on heating at 280 &deg;C was shown by Pd nanoparticles, however, partial oxidation of the sample was also noticed in the XRD pattern. SEM images of as synthesized Ag, Fe, Pd and Zn nanoparticles revealed agglomeration, whereas SEM images of Pd nanoparticles heated at 280 &deg;C displayed spherical particles clustered together.