Polyelectrolyte assisted synthesis and enhanced catalysis of silver nanoparticles: Electrocatalytic reduction of hydrogen peroxide and catalytic reduction of 4-nitroaniline

A facile method was developed for the one-step synthesis of silver nanoparticles (AgNPs), co-stabilized by the polyelectrolyte poly(acrylamide-co-diallyldimethylammoniumchloride) (PAD,A) and the silicate matrix N1-(3-trimethoxysilylpropyl)diethylenetriamine (TPDT). Here, TPDT acted as reducing agent and both PADA and TPDT served as capping agent for AgNPs. As PADA improved the catalytic properties of AgNPs, its concentration was optimized and the optimum concentration of PADA was found to be 1 wt.% among the concentrations 0.25, 0.5, 1 and 2 wt.%. The AgNPs were characterized using UV-vis absorption spectroscopy, HRTEM, EDX, SAED and FTIR analyses. The PADA(1)-Ag-TPDT NPs showed the better catalytic activity towards electrochemical reduction of H2O2 and catalytic conversion of 4-nitroaniline (4-NA) to p-phenylenediamine (PPD). The PADA(1)-Ag-TPDT NPs was used to construct the non-enzymatic electrochemical sensor for the detection of H2O2. Using the linear sweep voltammetry (LSV) and square wave voltammetry (SWV) techniques, the lowest experimental detection limits attained for H2O2 sensing were 5 and 0.2 mu M, respectively. Moreover, remarkably a fast conversion of 4-NA to PPD was observed over the PADA(1)-Ag-TPDTNPs catalyst with a rate constant of 0.096 s(-1) and the product (PPD) formation was confirmed by H-1 NMR spectroscopy. (C) 2016 Elsevier B.V. All rights reserved.