Corrosion Resistance of Porphyrin-Nickel electrode in 8 M NaOH solution

Nickel is one of the most important metals that was used in different industries such as electroplating, electroforming [1] and production of stainless steel [2]. In alkaline media, hydrogen was diffused in Nickel electrode and its corrosion was occurred. In this work the corrosion behavior of Porphyrin-Nickel electrode in 8 M NaOH solution was investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and polarization techniques. The porphyrin molecule, as a Lewis acid with a network of conjugated π-electron systems and four nitrogen atoms at its core, possesses the molecular frame of a potential corrosion coating. It is a tetradentate chelating agent with strong bonding capability and evident ability to interact with surfaces by several physical and chemical mechanisms [3]. The Tafel plots reports that porphyrin coating decrease the corrosion rate of Ni electrode. The result show that Porphyrin coating also exhibited higher charge transfer and polarization resistance compared to plain Nickel electrode.