Corrosion protection of galvanized steel and electroplating steel by decanoïc acid in aqueous solution: Electrochemical impedance spectroscopy, XPS and ATR-FTIR

The inhibiting action of decanoïc acid towards the corrosion behaviour of galvanized steel and electroplating steel in aqueous solution has been studied using electrochemical impedance spectroscopy (EIS) techniques. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. Results obtained revealed that decanoïc acid is an effective inhibitor. The better performance was obtained in the case of electroplating steel. X-ray photoelectron spectroscopy surface analysis shows that, decanoïc acid is chemisorbed on surface of galvanized steel and electroplating steel. These studies have shown that the active site for binding the film on metal surface is the anionic carboxylate head. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to identify the nature of the deposits on the metal surface.