Facile Synthesis, Characterization and Catalytic Function of Gelatin Stabilized Gold Nanoparticles

Abstract

In the present investigation, we report a new one phase, one pot method for synthesis of 3.5 ± 0.7 nm average sized gelatin capped gold nano particles (Gel-AuNPs) using strong reductant NaBH₄ in aqueous system at room temperature. Size controlled Gel-AuNPs were characterized by UVVisible, STEM, XRD, DLS and FT-IR. Spherical Gel-AuNPs showed excellent catalytic activity for reduction of three differently charged dyes eosin B (EB), methylene blue (MB) and rose bengal (RB) in the presence of NaBH₄. The study revealed that 100% reduction of EB, MB and RB dyes was carried out in just 150 sec. The developed catalyst was easy to recover and capable to be reused three times. The process of reduction rate and kinetics of dyes was monitored using UVVisible spectrophotometer. A plot of lnC Vs time (sec) showed that reaction follows the first order kinetics. Rate constant (K) was determined for EB, MB and RB reduction at 10 ìM, which was found as 2.735 x10^-2 sec-1, 2.738 x 10^-2 sec^-1 and 2.55 x 10^-2 sec^-1, respectively. The study revealed that catalytic reduction of dyes by Gel-AuNPs in aqueous medium is environmental friendly in terms of recovery of catalyst, is exceptionally fast and hence extremely economical