Mentha pulegium extract as a natural product for the inhibition of corrosion. Part I: electrochemical studies

Abdelkader Khadraouia*, Abdellah Khelifaa, Hocine Boutoumia & Belkheir Hammoutiba Laboratoire de Génie Chimique, Département de Chimie Industrielle, Faculté de Technologie, Université Saâd Dahlab de Blida, BP 270, Route de Soumaâ, Blida 09000, Algeriab LCAE-URAC18, Faculté des Sciences, Université Mohammed Premier, Oujda, Morocco*Corresponding author. Email: khadraoui.abdelkader@gmail.comThe inhibitory effect of Mentha pulegium extract (MPE) on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy. The inhibition efficiency of MPE was found to increase with the concentration and reached 88% at 33% (v/v). Polarisation measurements show that the natural extract acted as a mixed inhibitor. The remarkable inhibition efficiency of MPE was discussed in terms of blocking of electrode surface by adsorption of inhibitor molecules through active centres. The adsorption of MPE was found to accord with the Temkin isotherm.