Zinc metal at a new ZnO nanoparticles modified carbon paste electrode: A cyclic voltammetric study

Abstract

A new carbon paste electrode modified with ZnO nanoparticles was prepared and used to study the electro oxidation of zinc ions in solution by cyclic voltammetry (CV) method. The modified electrode displayed strong resolving function for the overlapping voltammetric response of zinc into one welldefined peak. The potential difference between Epa and Epc was > 200 mV, the range of which referred to the quasi-reversible mechanism. The kinetic of electrode was studied in the range of temperature 15-30 °C. The data of voltamograms showed the negative shift increased with increase of temperature, the result of which referred to the diffusion electron transfer in redox process of zinc oxidation. Diffusion coffining was calculated from Sevcik-Randles equation and thus equaled to 1.01×10-7. The rate constant was equal to 5.2×10-8 and 3.3×10-8 for oxidation and redaction respectively. And the peak current of zinc increased linearly with its concentration in the range of 2.0- 20.0 ppm.