Electrochemical and Quantum Chemical Studies of 5-[(4-Chlorophenoxy) Methyl]-4H-1,2,4-Triazole-3-Thiol on the Corrosion Inhibition of 6061 Al Alloy in Hydrochloric Acid

Abstract

Corrosion inhibition studies of 5-[(4-chlorophenoxy) methyl]-4H-1, 2, 4-triazole-3-thiol (CMTT) on 6061 Al alloy in 0.05 M HCl were carried out at different concentrations and temperatures. Weight loss method, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed in the study. Higher concentration and temperature were found to improve the efficiency of inhibitor. Highest corrosion resistance of 95.29% was recorded with 100 ppm CMTT at 333 K. Adsorption of the inhibitor was spontaneous as indicated by Langmuir adsorption isotherm. Thermodynamic parameters, SEM, AFM results indicated that inhibitor used protects the alloy from corrosion. Quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), dipole moment (l) and Mulliken charges are calculated. Quantum chemical calculations also endorsed experimental information and the adsorption of inhibitor molecules onto the metal surface.