Electrochemical and surface analytical characterization study of the inhibition effect of boiled red onion extract on tin corrosion in 0.2 M Maleic acid medium.

Abstract

The inhibition efficiency of boiled red onion skin extracts (BROE) against tin corrosion in 0.2 M Maleic acid has been studied using electrochemical and surface analytical methods. The electrochemical polarization curves displayed the active/passive transition of the anodic behavior of the tin electrode. The electrochemical impedance measurements demonstrated the effect of increasing BORE concentration on the inhibition efficiency (η %) (to a ηmax = 94% at 300 mg/L of BORE). The inhibition mechanism is attributed to the formation of adsorbed protective layers, on the metal surface, that fit the Langmuir adsorption isotherm model. Increasing the temperature hindered the η values.