Investigation of the Effect of Penicillin as a Green Corrosion Inhibitor for Mild Steel Using Electrochemical Techniques

Document Type : Research Paper




In this paper, the effect of penicillin G drug as a green corrosion inhibitor on mild steel in 1.0 M
hydrochloric acid solution has been investigated using potentiodynamic polarization, electrochemical
impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency
was found to increase with increasing inhibitor concentration. Potentiodynamic polarization
measurements indicated that penicillin G is a mixed type inhibitor. Furthermore, it has been
demonstrated that the electrochemical noise (EN) technique under open circuit conditions as the only
truly noninvasive electrochemical method can be employed for the quantitative evaluation of
corrosion inhibition. This can be done using the standard deviation of partial signal (SDPS) for
calculation of the amount of noise charges at the particular interval of frequency, thereby calculate
the inhibition efficiency (IE) of an inhibitor. These IE values show a reasonable agreement with those
obtained from potentiodynamic polarization and EIS measurements.