Biogenic synthesis of silver nanoparticles, sensing and photo catalytic activities for bromothymol blue

Abstract

Cyanidin 3, 5-di-O-glucoside (anthocyanin) was used for the large scale fabrication of silver nanoparticles (AgNPs) in absence and presence of externally added stabilizing agent for the first time. The AgNPs were characterized by using EDX, TEM, XRD, FTIR and zeta potential, which were used a catalyst to the oxidative decolorization of bromothymol blue with sodium borohydride. Hydrogen peroxide (H2O2) catalyzes the degradation of dye under sun light irradiation. The degradation followed fractional order kinetics with [H2O2]. Potassium iodide, methanol, ascorbic acid, potassium bromate, and EDTA were also used to decide the participation of radical oxygen species (ROS) and holes-electrons (h+-e−) during the dye degradation. Activation energy (Ea = 49.7 kJ/mol), enthalpy (ΔH# = 45.5 kJ mol−1) and entropy of activation (ΔS# = - 90.3 JK−1 mol−1) were calculated for the dye degradation. Nitrogen and oxygen containing radicals such as 1, 1- diphenyl -2- picrylhydrazyl (DPPH) and galvinoxyl were used to evaluate the antiradical activities of anthocyanin and AgNPs. The sensing properties of AgNPs enhanced with increasing anthocyanin concentrations.