Electrochemical and Theoretical Study of Kelussia odoratissima Mozaff. Extract as an Eco-friendly Corrosion Inhibitor for Carbon Steel in 0.5 M Sulphuric Acid Solution

In this project, performance of Kelussia odoratissima Mozaff extract for protection of carbon steel against corrosion in 0.5 M sulphuric acid solution was evaluated with common methods of weight loss, polarization at 25°C and electrochemical impedance spectroscopy (EIS). The results of all three methods were shown that the highest percentage of inhibition was obtained for 500ppm of inhibitor. By using the results of polarization tests, the extract was diagnosed as mixed corrosion inhibitor. Investigation of immersion time of carbon steel with weight loss method, indicate that for lower concentration of the extract, the protection effect was reduced with increase the immersion time. But, in higher concentration of the extract (500ppm) the protection effect was remained constant. Investigation of the effect of temperature on the performance of the extract at temperature range of 25 - 65°C indicates a decrease in the inhibition of the extract by increasing the temperature. Adsorption of molecules of Kelussia odoratissima Mozaff extract on the carbon steel is agree with Langmuir isotherm. The adsorption of molecules of Kelussia odoratissima Mozaff extract on the carbon steel were stated as physical adsorption. The results of quantum studies confirmed the results of previous methods.

Keywords:

Kelussia odoratissima Mozaff extract , Corrosion inhibitor , Carbon steel , H2SO4 , Polarization method , Electrochemical impedance method , Weight loss method , Electrochemical quantum method.