1,2,3-triazolyl-linked benzimidazolone derivatives as new eco-friendly corrosion inhibitors for mild steel in 1 M HCl solution: Experimental and computational studies

Abstract

Three heterocyclic derivatives of 1,2,3-triazolyl-linked benzimidazolone, named Ph-TLB, OCH3Ph-TLB, and NO2Ph-TLB, were studied for their ability to inhibit corrosion of mild steel (MS) in a 1 M HCl solution using various techniques, including potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX) analysis. The results showed that all three derivatives were effective inhibitors of corrosion, with NO2Ph-TLB showing the highest inhibition effectiveness (96.6 %) and followed by Ph-TLB (95.2 %) and OCH3Ph-TLB (92.6 %) at an optimal concentration of 10−4 M and a temperature of 298 K. The PDP curves obtained in the presence of different organic compounds revealed that the inhibitors were of a mixed nature. The inhibitors were found to adsorb onto the surface of MS according to the Langmuir isotherm, and their adsorption and thermodynamic parameters were evaluated. SEM-EDX and X-ray diffraction (XRD) studies show the adsorption of studied compounds which forms a protective layer over the mils steel surface. Density Functional Theory (DFT) calculations and Monte Carlo (MC) simulations were applied to analyse the interactions of synthesized inhibitors with MS surface along with corrosive species as it happens in the corrosive environment. In addition, The Fukui indices were computed for the determination of the most plausible nucleophilic and electrophilic attack sites.