A comparative study of electrocatalytic reduction of hydrogen peroxide at carbon rod electrodes decorated with silver particles

Abstract

Herein, comparative studies of silver particles electrodeposition in a water-glycerine solution containing silver ions and sodium dodecyl sulfate (SDS) are presented. The electrodepositions were carried out at pure metal cathodes and after covering them with a Nafion® layer. These studies have shown that a shape and amount of silver deposit depend on cathode material, presence/absence of the Nafion® layer, and electrodeposition regime. The morphology and chemical composition of obtained silver particles (Ag-Ps) were characterized using FE-SEM and EDS, respectively. Carbon rod (Crod) electrodes were decorated with synthesized silver particles and then protected by the Nafion® layer. The Crod@Ag-Ps electrodes were used as a working electrode for detection and determination of hydrogen peroxide by cyclic voltammetry (CV) and chronoamperometry (ChA). All electrodes showed good electrocatalytic activity toward H2O2 reduction when compared to a carbon rod electrode. Moreover, the Crod@Ag-Ps electrode exhibited a linear response toward the reduction of H2O2 over a very wide range of H2O2 concentrations. For the Crod@Ag-Ps sensor based on silver particles synthesized on the stainless-steel substrate, a high-sensitivity determination of H2O2 of about 0.128 µA cm−2 µM−1 can be attained with a detection limit (LOD) and quantification limit (LOQ) of 0.10 mM and 0.33 mM, respectively.