Electrochemical and theoretical investigation of triazole derivatives on corrosion inhibition behavior of copper in hydrochloric acid medium

The inhibition effect of three triazole derivatives namely 4-amino-4H-1,2,4-triazole-3thiol (HIT), 4-amino-5-methyl-4H-1,2,4-triazole-3thiol (AMTT) and 4-amino-5-ethyl-4H-1,2,4-triazole-3thiol (AETT) have been investigated against the corrosion of copper in 0.5 M HCl solution. The investigations were analyzed using potentiodynamic polarization, electrochemical impedance, weight loss methods and quantum chemical studies. Potentiodynamic polarization measurements indicate that all three examined compounds are cathodic type inhibitors. Among the studied compounds, 4-amino-5-ethyl-4H-1,2,4-triazole-3thiol exhibited the best inhibition efficiency 96.09% at 2.58 mM. The adsorption of these compounds obeyed the Langmuir adsorption isotherm. The electronic properties obtained using quantum chemical approach, were correlated with the experimental results. (C) 2013 Elsevier Ltd. All rights reserved.