Abstract:

The cause of Warburg impedance on the impedance spectra for copper electrode in low-conductivity solution has been studied. The slopes of Randles plots (Warburg coefficients) do not change with dissolved oxygen concentration and strring rate, but they increase with the increase of the pH of solution and driesion time. The experimental results show that the Warburg twedance at low frequencies is caused by the diffusion of copper ions from the inner side to the outer side of the oxide film on the surface of copper electrode.

Key words: Copper electrode, Low-conductivity solution, Warburg impedance, Warburg coefficient, Diffusion