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

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 (R) layer. These studies have shown that a shape and amount of silver deposit depend on cathode material, presence/absence of the Nafion (R) 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 (C-rod) electrodes were decorated with synthesized silver particles and then protected by the Nafion (R) layer. The C-rod@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 C-rod@Ag-Ps electrode exhibited a linear response toward the reduction of H2O2 over a very wide range of H2O2 concentrations. For the C-rod@Ag-Ps sensor based on silver particles synthesized on the stainless steel substrate, a high-sensitivity determination of H2O2 of about 0.128 mu A cm(-2) mu M-1 can be attained with a detection limit (LOD) and quantification limit (LOQ) of 0.10 mM and 0.33 mM, respectively.

Automated summary

The study demonstrates the influence of electrodeposition of silver particles on the shape and amount of silver deposits, as well as the electrocatalytic performance of synthesized silver particles. The silver particle electrodes prepared under different conditions show high sensitivity and accuracy in detecting H2O2.