Extract of Camellia sinensis as Green Inhibitor for the Corrosion of Mild Steel in Aqueous Solution

Corrosion inhibition of mild steel used in water station in 35 ppm aluminum sulfate and 10 ppm chloride solution by Camellia sinensis leaves extract was studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques at 30 degrees C. Results show that the inhibition efficiency increases with increasing concentration of the extract and decreases with increasing temperature. Inhibitive effect was afforded by adsorption of the extract's components which was found to accord with Langmuir adsorption isotherm. Inhibition mechanism is deduced from the temperature dependence of the inhibition efficiency and was further corroborated by the values of activation parameters obtained from the experimental data.