Synthesis of silver/multi-walled carbon nanotubes composite and its application for electrocatalytic reduction of bromate

The silver nanoparticles decorated multi-walled carbon nanotubes composite (Ag/MWNTs) was prepared and used to fabricate a modified electrode. The composite was examined by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of Ag/MWNTs modified glassy carbon electrode (Ag/MWNTs/GCE) was evaluated for electro-catalytic activity towards bromate reduction in buffer solutions by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and multi-potential steps method. The experimental data shows that the silver nanoparticles were well deposited on MWNTs and Ag/MWNTs/GCE exhibit high electrocatalytic activity towards bromate reduction. It is proposed that firstly the bromate ions diffused to the active sites and then the electrochemical reduction occurred. The bromate reduction on Ag/MWNTs/GCE was proved to be an irreversible and diffusion controlled process. Furthermore, Ag/MWNTs/GCE is characterized by good stability and relatively high sensitivity with respect to bromate concentration.

► Silver/multi-walled carbon nanotubes composite was synthesized by reduction method.
► The Ag/MWNTs composite has good electrochemical activity and stability.
► Electrocatalytic reduction of bromate on Ag/MWNTs modified electrode was investigated.
► This electrode exhibit remarkable catalytic performance for bromate reduction.
► Ag/MWNTs modified electrode could be employed as an amperometric sensor for bromate.