Assessment of three quinolin-8-ol-imidazole hybrids as corrosion carbon steel inhibitors in acidic conditions employing practical and theoretical methodologies

Abstract

Three hybrids of quinolin-8-ol-imidazole were scrutinized as corrosion inhibitors in 1 M HCl for carbon steel (Cstl). These hybrids are 5-((2-(4-(dimethylamino)phenyl)-4,5-diphenyl-1H-imidazol-1-yl)methyl)quinoline-8-ol (Quin-Amino), 5-((4,5-diphenyl-2-(p-tolyl)-1H-imidazol-1-yl)methyl)quinoline-8-ol (Quin-Tolyl), and 5-((2-(4-bromophenyl)-4,5-diphenyl-1H-imidazol-1-yl)methyl)quinoline-8-ol (Quin-Br). The current research includes a mixture of methods. In addition to computational approaches, several experimental approaches were employed, such as electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM-EDX), UV–vis spectroscopy, and potentiodynamic polarization (PDP). The investigated hybrids' corrosion resistance was encountered to be concerned by the concentration, temperature, and chemical structure, which attained a maximum of 96.1 % for Quin-Amino, 93.4 % for Quin-Tolyl, and 92.5 % for Quin-Br at 10⁻³ M, respectively. The PDP results illustrated that the studied hybrids performed as mixed-type inhibitors. In addition, the chemisorption of these hybrids on the Cstl surface obeyed the Langmuir adsorption isotherm. SEM-EDX confirmed that the effectiveness of the three hybrids lies in their capability to develop an organic layer on the Cstl surface. The density functional theory (DFT) was employed for theoretical calculations. Molecular dynamics (MD) simulations manifest that hybrids are oriented beneficially on the Fe (110) surface, providing a high surface coverage and thus a high inhibition performance.