Inhibition behavior of Fadogia andersonii Robyns leave extract for mild steel corrosion in acidic media: Electrochemical and surface investigation

Nkem B. Iroha

Abstract

The aim of this research is to evaluate the effectiveness Fadogia andersonii Robyns (FAR) as a corrosion inhibitor for mild steel in an acidic media (1 M HCl). The corrosion inhibition of FAR was characterized by surface morphology, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss methods. The results showed that inhibitor performance depends on both concentration and temperature. The inhibition efficiency decreases with increasing the temperature from 303 to 323 K but increases with increase in concentration, reaching a maximum value of 91.0% at the highest concentration of 300 ppm at the temperature of 303 K; from weight loss measurement. Polarization study revealed that the extract behaves as mixed-type inhibitor. The inhibitor molecules adsorb on the surface of the metal, following Langmuir`s adsorption isotherm The micrograph from SEM showed that the inhibitor adsorbed onto the metal surface which indicate less damage on the metal surface in the presence of FAR.