Mild steel corrosion inhibition by aqueous extract of Hyptis Suaveolens leaves

Hyptis suaveolens leaf extract (HSLE) as corrosion inhibitor in 1 M H 2 SO 4 was evaluated using mass loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The extract was found to efficiently inhibit the corrosion process in 1 M H 2 SO 4 and inhibition efficiency increased with increasing extract concentration. Maximum inhibition efficiency of HSLE in 1 M H 2 SO 4 was found to be 95 %. The potentiodynamic polarization results revealed that HSLE acted as mixed-type inhibitor. The adsorption of the studied inhibitor on mild steel obeyed Langmuir adsorption isotherm. The nature of protective film formed on the surface of the mild steel was confirmed by FT-IR, XRD and SEM techniques. This study clearly shows the efficiency of HSLE for control of mild steel corrosion in 1 M H 2 SO 4 solutions.