Adsorption and electrochemical studies of Pimenta dioica leaf extracts as corrosion inhibitor for mild steel in hydrochloric acid

Alcohol and water extracts of the leaves of Pimenta Dioica (PD) have been investigated as non toxic corrosion inhibitors for mild steel in acidic medium (0.5 M and 1 M HCl). Corrosion rates were evaluated at 303 K, 308 K and 313 K using electrochemical impedance spectroscopy and polarization techniques. Basic computational calculations for the component molecules and adsorption studies were also carried out for estimating the energies of frontier orbitals and the mechanism of corrosion inhibition. Electrochemical techniques reveal that PD extracts exhibit excellent inhibition efficiency and function as mixed type inhibitor at all these temperatures. Adsorption studies showed that the process follows Langmuir adsorption isotherm.