Interfacial impedance spectroscopy on electroplated nickel electrodes in chloride and sulphate solutions

ABSTRACT

The corrosion behaviour of the as-plated three different nickel electrodes has been investigated in 5 percent NaCl and 6 percent Na[2]SO[4] solutions by using impedance Spectroscopy technique. Ladder network equivalent circuits and simple equivalent circuits have been used to explain the electrochemical behaviour of the nickel electrodes in the above solutions. Analysis of the impendence spectra showed that the impedance parameters depended on the electrode type and the applied potential in chloride and sulphate solutions. In the chloride solution the three nickel electrodes exhibited rapid pitting corrosion while in sulphate solution the electrodes were rendered passive with very low corrosion rate