Rapid microwave synthesis of silver nanoparticles capped by soluble starch and its catalytic activity

A facile, green and cost-effective route was used to fabricate silver nanoparticles using a domestic microwave (2450 MHz, 1000 W) for the reduction of the aqueous AgNO3 solution (Ag precursor) and soluble starch, serving as a reducing and capping agent, in an alkaline medium (sodium hydroxide) without using any other chemical reducing agent. The synthesized nanoparticles were characterized by a UV-Visible spectroscopy, detecting the surface plasmon resonance band at 410 nm. According to transmission electron microscopy, the fabricated AgNPs were found to be spherical with an average particle diameter of 13.2±1.02 nm. Furthermore, the energy dispersive spectroscopy spectra exhibited a characteristic peak at 3 KV, confirming the formation of elemental silver particles. In addition, the selected area electron diffraction with bright circular spots and X-ray diffraction spectra with characteristic peaks revealed the formation of highly crystalline face-centered cubic metallic silver nanoparticles. Furthermore, Fourier transform infrared spectroscopy revealed the role of starch in the stabilization of silver nanoparticles. The as-synthesized nanoparticles showed a strong catalytic activity through the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. Copyright © 2017 American Scientific Publishers All rights reserved.