Copper Metal at New CuO Nanoparticles Modified Carbonpaste Electrode: Selective Voltammetric Determination

A new carbon paste electrode modified with CuO nanoparticles was prepared, and used to study the electro oxidation of copper ions in solution by cyclic voltammetry (CV) method. The modified electrode displayed strong resolving function for the overlapping voltammetric response of copper into one well-defined peak. The potential difference between Epa and Epc was > 200 mV; this range referred to the quise-reversible mechanism. The kinetic of electrode was studied at the temperature range from 15 ~ 35 ^oC; the data of voltamograms showed the increase of temperature caused increase of negative shift, which suggested the diffusion electron transfer in the redox process of copper oxidation. Diffusion coefficient was calculated from the Randles–Sevcik equation and was equal to 71.8 × 10^-4; the rate constant K was equal to 8.8 × 10^-7; the peak current of copper increased linearly with its concentration at the range of 0.2 ~ 2.0 ppm.