Some amino acids as corrosion inhibitors for copper in nitric acid solution

Abstract: The inhibition effect of five amino acids (AA) on the corrosion of copper in molar nitric solution was studied by using weight loss and electrochemical polarization measurements. Valine (Val) and Glycine (Gly) accelerate the corrosion process; but Arginine (Arg), Lysine (Lys) and Cysteine (Cys) inhibit the corrosion phenomenon. Cysteine is the best inhibitor. Its efficiency increases with the concentration to attain 61% at 10−3 M. Correlation between the quantum chemical calculations and inhibition efficiency was discussed using semi-empirical methods (AM1 and MNDO). [Copyright &y& Elsevier]