Anticorrosive properties of two 3,5-disubstituted-4-amino-1,2,4-triazole derivatives on copper in hydrochloric acid environment: Ac impedance, thermodynamic and computational investigations

The evaluation of inhibition performance of two 3,5-disubstituted-4-amino-1,2,4-triazoles, namely 3,5-bis(4-methylphenyl)-4-amino-1,2,4-triazole (MeAT) and 3,5-bis(4-methoxyphenyl)-4-amino-1,2,4-triazole (MxAT) on copper corrosion in normal acid environment (1 M HCl), was done by electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Comparative study of MeAT and MxAT was carried out and substituent effect on corrosion inhibition performance was discussed. Modelling of the dielectric data was also performed for MxAT in order to closely monitor the variation of permittivity. The results showed that the investigated 1,2,4-triazole derivatives are efficient corrosion inhibitors for copper in 1 M HCl and an inhibition efficiency of 87.9% was exhibited at 10(-3) M concentration of MxAT at 303 K. Thermodynamic data from adsorption isotherms and activation energies were determined and discussed. It was shown that the adsorption of MxAT molecules fits Langmuir isotherm model and the corresponding value of the standard Gibbs free energy of adsorption ( Gads) ois associated to a chemisorption mechanism. Computational studies by DFT and Monte Carlo simulation (MCs) were also conducted to correlate the inhibition properties and quantum chemical parameters of the investigated inhibitors.