ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 59, Number 2
JKCSEZ 59(2)
April 20, 2015 

Inhibition effects of histidine (His), methionine (Met) on the corrosion of nickel were investigated in deaerated 0.5 M HCl and 0.5 M H2SO4 solution. All the inhibition efficiency for the nickel corrosion depended on the anodic inhibition. Amino acid adsorption process on nickel surface in the solution of HCl can be explained by modified Langmuir isotherm, however, in the solution of H2SO4 by Temkin logarithmic isotherm due to the interaction between the adsorbed molecules. The molecule of histidine dissolved in HCl-solution were physically adsorbed due to the electrostatic interaction between the surface of {Ni-Cl-} and the {-NH3 +} and {-NH+=} of His. However the other cases of adsorption in this investigation can be explained by chemical adsorption between the empty d-orbital of Ni and the lone pair of electron in His and Met.