Characterization of adsorption of 5-carboxy-3-amino-1,2,4-triazole towards copper corrosion prevention in neutral media

Adsorption behavior of 5-carboxy-3-amino-1,2,4-triazole (COOH-ATA) on copper in neutral (pH 7.4) borate buffer solutions with and without 0.01 M NaCl was studied. Electrochemical polarization methods show significant suppression of the anodic and cathodic currents on the polarization curves in the presence of COOH-ATA. Chronopotential diagrams show increase of open circuit potential during adsorption. Ellipsometric studies has allowed to estimate the free energy of adsorption. X-ray photoelectron spectroscopy was applied to examine the surface composition after COOH-ATA adsorption from the inhibitor solution. Spectra analysis shows oxidation of copper to Cu+ and Cu2+ with surface complex formation. Protective properties in humid air and salt fog chamber of such layer are discussed. (C) 2019 Elsevier Ltd. All rights reserved.