TEM and XAS Study of Silver Nanoparticles Formed in Phaseolus vulgaris

Abstract

The phytoremediation can be used to recover precious metals like gold, silver, platinum and palladium, indicating that there is a wide opportunity for use it as a remediation technology in mining. The alfalfa alive was used to reduce the silver and forming silver nanoparticles Ag (0). The plant Phaseolus vulgaris (beans) was used to form silver nanoparticles through bioreduction of Ag (I) to Ag (0) in the living plant. Two groups of plants were used. One group of plants grew at garden soil and the other in cotton. In both cases, a solution of AgNO3 was added initially in a concentration of 0.01M then the concentration was changed to 0.1mm. The samples were analyzed with X-Ray Absorption Spectroscopy (XAS) at the Stanford Synchrotron Radiation Laboratory (SSRL) and later with Transmission Electron Microscopy (TEM). Analyzing the media of cultivation in soil and cotton and also in the roots of the plants, silver was found as silver oxide (AgO). In stem and leaves silver was found as Ag (0). The XAS spectra were adjusted for more accurate results. The plant has the ability to reduce the valence of silver and form nanoparticles. The TEM images show that the average particle size is 18 nm, showing in various forms and a greater number of them in the leaves of plants grown in soil.