Electrochemical and theoretical comparisons of the anticorrosive effectiveness of quinazoline-based inhibitors, Q–NO₂ and Q–N(CH₃)₂ for corrosion inhibition of mild steel in 1.0 M HCl

• S. Elmansouri¹, R. Lachhab¹, M. Galai¹, M. Rbaa², O. Dagdag³, H. Kim³, A. Berisha⁴, M. Ouakki¹, A.A. Al Obaid⁵ and M.E. Touhami¹

¹ Advanced Materials and Process Engineering, Faculty of Sciences, Ibn Tofaïl University, PO Box 133, Kenitra 14000, Morocco
² The Higher Institute of Nursing Professions and Health Techniques of Casablanca, P.O. Box, 20250 Casablanca, Morocco
³ Department of Mechanical Engineering, Gachon University, Seongnam 13120, Republic of Korea
⁴ Department of Chemistry, Faculty of Natural and Mathematics Science, University of Prishtina, 10000 Prishtina, Kosovo
⁵ Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia

Abstract: In this study, the corrosion inhibition abilities of two new quinazoline-based inhibitors (Q–NO₂ and Q–(CH₃)₂) were investigated for mild steel immersed in a 1 M hydrochloric acid solution. This study applied multiple experimental and computational approaches, including electrochemical impedance spectroscopy, potentiodynamic polarization experiments, and quantum chemical topology via density functional theory (DFT). Molecular dynamics (MD) simulations were also performed. The results demonstrate that there is a corrosion protection with both compounds, with Q–(CH₃)₂ achieving an inhibition efficiency of 96.3% and Q–NO₂ exceeding an inhibiting efficiency of 92.2% at a 10^–3 M concentration. The inhibition efficiency increased with increasing inhibitor concentrations. Temperature variation studies for both compounds were performed between 298 and 328 K at optimal concentrations and confirmed a mixed-type inhibition characterized by both polarization data and gravimetric studies. The adsorption data indicate that both inhibitors follow the Langmuir isotherm model. In addition, surface investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed that the compounds facilitated the formation of a protective coating on the metal surface and reduced corrosion. The originality of this work lies in the synthesis of new molecules derived from quinazoline, evaluated for the first time as corrosion inhibitors in a 0.1 M hydrochloric acid environment. The results obtained are very satisfactory owing to these compounds, which not only provide remarkable protection but also have specific structural characteristics. From a stereochemical point of view, the presence of donor and acceptor groups near the aromatic rings increases the electron density and strengthens interactions with the steel surface. Owing to this configuration, these molecules achieve high inhibition efficiencies, even at low concentrations. Therefore, this study provides valuable insights into the development of effective corrosion inhibitors based on their molecular structure.

Keywords: corrosion inhibition, electrochemical studies, SEM-EDX, adsorption, theoretical calculations

Int. J. Corros. Scale Inhib., 2025, 14, no. 4, 2050-2082
doi: 10.17675/2305-6894-2025-14-4-17

Download PDF (Total downloads: 11)

Back to this issue content: 2025, Vol. 14, Issue 4 (pp. 1685-... (in progress))