Colorimetric sensing of Fe3+ and Hg2+ and photocatalytic activity of green synthesized silver nanoparticles from leaf extract of Sonchus arvensis L.
In the present study, an eco-friendly method was reported for green synthesis of silver nanoparticles (AgNPs) using Sonchus arvensis (SA) leaf extract. Phytochemical analysis of plant extract revealed the presence of flavonoids, tannins, glycosides, and alkaloids which might be ascribed as potential capping, reducing, and stabilizing agent in the process. SA-AgNPs were found stable with no evidence of agglomeration after one week. UV-visual spectroscopy showed salient SPR peak of Ag0 at 440nm, and calculated bandgap (3.2 eV) explained semiconducting behaviour of NPs. FT-IR spectra elucidated the functional groups of SA extract attached with Ag0. TEM and XRD revealed the spherical shape of SA-AgNPs with an average particle and crystalline size of 25 ± 5 and 16 ± 1nm respectively. The colorimetric method was employed for quick detection of heavy metals in aqueous medium using SA-AgNPs. Obtained NPs found to be highly selective and sensitive to Fe3+ and Hg2+ metal ions at a detection limit of 10-3 M and thereby acts as noble solid bio-sensor. SA-AgNPs showed strong catalytic efficiency against methylene blue compared other dyes in the presence of sunlight and completely degraded the dye within 1 hour. This catalytic efficiency was observed due to lower bandgap value (3.2eV) of SA-AgNPs.