investigation of the effect of penicillin as a green corrosion inhibitor for mild steel using electrochemical techniques

in this paper, the effect of penicillin g drug as a green corrosion inhibitor on mild steel in 1.0 mhydrochloric acid solution has been investigated using potentiodynamic polarization, electrochemicalimpedance spectroscopy (eis) and electrochemical noise (en) techniques. the inhibition efficiencywas found to increase with increasing inhibitor concentration. potentiodynamic polarizationmeasurements indicated that penicillin g is a mixed type inhibitor. furthermore, it has beendemonstrated that the electrochemical noise (en) technique under open circuit conditions as the onlytruly noninvasive electrochemical method can be employed for the quantitative evaluation ofcorrosion inhibition. this can be done using the standard deviation of partial signal (sdps) forcalculation of the amount of noise charges at the particular interval of frequency, thereby calculatethe inhibition efficiency (ie) of an inhibitor. these ie values show a reasonable agreement with thoseobtained from potentiodynamic polarization and eis measurements.