Computational, MD simulation, SEM/EDX and experimental studies for understanding adsorption of benzimidazole derivatives as corrosion inhibitors in 1.0 M HCl solution

The adsorption and corrosion inhibition performance of two benzimidazole derivatives, namely:2-(allylthio)-1H-benzo[d]imidazole (SHA) and bis((1H-benzo[d]imidazole-2-yl)thio)methane (BB1C) were studied as a corrosion inhibitors for mild steel (MS) in 1.0 M HCl solution using Weight Loss (WL) measurements, Potentiodynamic Polarization (PDP), Electrochemical Impedance Spectroscopy (EIS), Scanning Electron Microscopy(SEM) and Energy Dispersive X-ray (EDX) analysis. The kinetics of corrosion retardation were inspected by polarization studies, and the respective achievements declared that both compounds could retard corrosion reactions via cathodic/anodic (mixed) inhibition mechanism. The adsorption process on MS surface obeyed Langmuir isotherm. Adsorption and thermodynamic parameters were also evaluated. SEM/EDX analysis strongly supports the obtained results and confirms the existence of a barrier film on the metal surface. Our findings provide deeper insights into understanding the interaction mechanisms of SHA and BB1C with MS surface. Experimental outcomes support the outcomes obtained from DFT and Molecular dynamic (MD) simulation. (C) 2020 Elsevier B.V. All rights reserved.