The inhibitory effect of certain imidazole derivatives grafted on 8-hydroxyqinoline on carbon steel corrosion in acidic medium: experimental and computational approaches

In this work, we scrutinized two imidazole derivatives grafted on 8-hydroxyqinoline, namely 5((2-(4-hydroxyphenyl)-4,5-diphenyl-1H-imidazol-1-yl)methyl)quinolin-8-ol (HDIQ) and 5((2-([1,1 & PRIME;-diphenyl]-4-yl)-4,5-diphenyl-1H-imidazol-1-yl)methyl)quinolin-8-ol (BDIQ), as corrosion inhibitors for carbon steel (CS) in HCl environment. Evaluation of their inhibitory properties was carried out using weight loss (WL) and electrochemical techniques such as potentiodynamic polarization curves (PDP) and electrochemical impedance spectroscopy (EIS). In addition, the metal surface was characterized by surface morphology analysis using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). The inhibitory efficiencies of HDIQ and BDIQ increase with concentration, reaching a maximum inhibitory efficiency of 90.8% for HDIQ and 87.5% for BDIQ at 10-3 M. Temperature effects on inhibitory efficiency were investigated in the [303-333 K] range. The adsorption of BDIQ and HDIQ onto the CS surface in the corrosive environment followed the Langmuir isotherm. Morphological SEM images provide satisfactory confirmation of the results obtained during WL and electrochemical tests. Quantum theoretical studies using density functional theory (DFT) and molecular dynamics (MD) simulations confirmed the experimental results.