The corrosion inhibition of copper in hydrochloric acid solutions by a tripeptide compound

The efficiency of glutathione as a non-toxic corrosion inhibitor for copper in 0.5 M HCl has been studied by using the weight-loss technique, cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Maximum protection efficiency reaches about 92.7% for glutathione at 10 mM concentration level. Results obtained from potentiodynamic polarization and impedance measurements are in good agreement. The adsorption of glutathione on copper surface follows Langmuir isotherm. The adsorption free energy of glutathione on copper (∼−32 kJ mol−1) reveals a strong physical adsorption of the inhibition on the metal surface.