Silver nanoparticles synthesized using Allium ampeloprasum L. leaf extract: Characterization and performance in catalytic reduction of 4-nitrophenol and antioxidant activity

A green approach for biosynthesis of silver nanoparticles (AgNPs) is developed using A. ampeloprasum leaf extract. The as-synthesized nanoparticles were characterized by UV visible, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Xray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and zeta sizer (ZS). The formation of AgNPs was confirmed by changing the colour of solution from colourless to light brown and the presence of absorption peaks between 420 and 440 nm using UV spectra. The TEM analysis of AgNPs showed the particle sizes ranged between 2 and 43 nm, with shapes of quasi-spherical, spherical, ellipsoidal, hexagonal and irregular. The crystalline and face centered cubic (FCC) structure of AgNPs was obtained by XRD study. In addition, the FTIR spectrum of AgNPs showed the presence of different functional groups that may be associated with the reduction of Ag ions to AgNPs. The yield of AgNPs was determined around 99.95% by ICP-MS quantification after centrifugal ultrafiltration. The biosynthesized AgNPs exhibited catalytic activity in the reduction of the toxic organic pollutant of 4-nitrophenol to 4-aminophenol, and antioxidant activity against DPPH center dot (2,2-diphenyl-1-picrylhydrzyl) and ABTS(+center dot) (2,2'azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)) radicals. This approach does not require any toxic substance, is quite cheap and readily to be performed in a single pot process. (C) 2018 Elsevier B.V. All rights reserved.