Synergistic experimental and theoretical investigation of organic inhibitors against mild steel corrosion in 1.0 M HCl

• A. El Karkouri¹, M. Khattabi², O. Kharbouch², A. Zaidi², K. Dahmani^1,3, S. Sibous¹, F. El Hajri¹, I. Saber¹, M. Galai², M. Cherkaoui^1,3 and S. Boukhris¹

¹ Laboratory of Organic, Inorganic Chemistry, Electrochemistry and Environment, Faculty of Sciences, Ibn Tofaïl University, PO Box 133, 14000, Kénitra, Morocco
² Laboratory of Advanced Materials and Process Engineering, Faculty of Sciences, Ibn Tofail University, PO Box 133, 14000, Kénitra, Morocco
³ Laboratory of Engineering, Sustainability and Innovation, Ecole Nationale Supérieure de Chimie (ENSC), University Ibn Tofail, PO Box 133, 14000, Kenitra, Morocco

Abstract: In this study, two newly synthesized nitrophenyl-substituted chromene derivatives, 2-amino-7,7-dimethyl-4-(2-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (ZE3-2-NO₂) and 2-amino-7,7-dimethyl-4-(3-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (ZE4-3-NO2₂, were investigated as corrosion inhibitors for mild steel in 1.0 M HCl solution. Electrochemical measurements showed that both compounds significantly reduced corrosion rates, with inhibition efficiencies of 91.1% and 88.5% at 298 K. Adsorption studies confirmed Langmuir-type chemisorption, while Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy analyses revealed the formation of a protective organic film. Quantum chemical calculations and molecular dynamics simulations supported stable adsorption on the Fe (110) surface and clarified the role of functional groups in metal coordination. This combined experimental and theoretical approach provides insights into structure activity relationships and supports the design of chromene based corrosion inhibitors.

Keywords: corrosion inhibition, mild steel, chromene derivatives, acidic medium, adsorption isotherm

Int. J. Corros. Scale Inhib., 2026, 15, no. 1, 201-228
doi: 10.17675/2305-6894-2026-15-1-10

Download PDF

Back to this issue content: 2026, Vol. 15, Issue 1 (pp. 1-... (in progress))