Corrosion of copper in aerated acidic pickling solutions and its inhibition by 3-amino-1,2,4-triazole-5-thiol

• Published in: Journal of colloid and interface science Vol. 306; no. 1; pp. 96 - 104
• Main Authors: Sherif, El-Sayed M., Erasmus, R.M., Comins, J.D.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01-02-2007; Elsevier
• Subjects: 3-Amino-1,2,4-triazole-5-thiol; Aerated acidic pickling solutions; Chemistry; Copper corrosion; Corrosion inhibition; Exact sciences and technology; General and physical chemistry; Raman spectroscopy; Copper corrosion; Aerated acidic pickling solutions; Corrosion inhibition; 3-Amino-1,2,4-triazole-5-thiol; Raman spectroscopy; Thiol; Corrosion; Transition metal; Raman spectrometry; Inhibition; Copper; Acidic solution
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2006.10.029

Corrosion of copper in aerated acidic chloride pickling (0.5 M HCl) solutions and its inhibition by 3-amino-1,2,4-triazole-5-thiol (ATT) have been investigated using electrochemical techniques and weight-loss measurements, along with Raman spectroscopy. Electrochemical measurements for copper after varied immersion periods of 0, 24, and 48 h showed that the presence of ATT and the increase of its concentration significantly decrease cathodic, anodic, corrosion (
j
Corr
) currents and corrosion rates (
K
Corr
), as well as the dissolution currents at 300 mV vs Ag/AgCl, while increasing polarization resistance (
R
p
), degree of surface coverage (
θ) and inhibition efficiency (IE%) to a great extent. Weight-loss measurements after different immersion periods of 6 to 48 h revealed that the dissolution of copper decreased to a minimum and the corresponding IE% increased with increasing ATT concentration. The detection of ATT molecules on the copper surface by Raman spectroscopy indicated that inhibition of copper corrosion is achieved by strong adsorption of ATT molecules onto the copper surface.
Potentiodynamic polarization curves for copper in aerated 0.5 M HCl after 0 (a), 24 (b), and 48 h (c) of electrode immersion without (1) and with 0.5 (2), 1.0 (3), and 5.0 mM 3-amino-1,2,4-triazole-5-thiol (ATT) (4) present.