Effect of SiC Nanoparticles on the Electrochemical Reduction Behaviors of Ionic Bismuth and Tellurium

Abstract

The effect of SiC nanoparticles on the electrochemical reduction behaviors of ionic bismuth and tellurium was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The results showed that the addition of SiC nanoparticles in the solution did not change the electrochemical reduction process of ionic bismuth and tellurium on Au electrode, as the shapes and numbers of the peaks in the cyclic voltammograms were not altered, although the peak potentials and peak currents varied a little. However, the electrochemical reduction of ionic bismuth was accelerated by introducing SiC nanoparticles in a Bi unitary solution system for the size reduction of the semicircles in EIS plots. Different from ionic bismuth, the electrochemical reduction of adsorbed HTeO₂ ⁺ to Te⁰ was inhibited and enlarged semicircles in EIS plots were observed. In contrast, the reduced semicircles in EIS plots revealed a promoting effect of SiC nanoparticles on the electrochemical reduction of dissociative HTeO₂ ⁺ to Te⁰. Bi₂Te₃/SiC composite has been synthesized by a co-depositing process in solutions containing ionic bismuth, tellurium and SiC nanoparticles combined with anneal treatment.