Corrosion Inhibition of Mild Steel in 1 M HCl Using N-benzylidenethiophene-2-sulfonamide: Experimental and Theoretical Investigations

Articles in Press

Document Type : Original Article

Authors

1 Al-Karkh University of Science, P.O. Box: 10001, Baghdad, Iraq

2 University of Technology, P.O. Box: 10001, Baghdad, Iraq

3 Science and Technology Department, Al-Ayen Iraqi University, AUIQ, P.O. Box: 64001, Thi-Qar, Iraq.

Abstract

This research investigates the corrosion inhibition performance of a newly developed Schiff base compound, N-benzylidenethiophene-2-sulfonamide (NB2S), for protecting mild steel (MS) in a 1 M hydrochloric acid (HCl) environment. A comprehensive evaluation was carried out through various techniques, including weight loss (WL) analysis, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and density functional theory (DFT). The mass loss findings indicated that NB2S’s inhibitory performance improved with concentration, achieving up to 95.86% efficiency at 0.005 M after a 24-hour immersion. Impedance analysis showed an increase in charge-transfer resistance and a decrease in double-layer capacitance, reflecting strong surface adsorption. PDP measurements revealed that NB2S suppresses cathodic and anodic reactions, acting as a mixed-type inhibitor. Adsorption followed the Langmuir isotherm model, with thermodynamic parameters indicating a spontaneous, exothermic adsorption process. Computational DFT results aligned with experimental observations, highlighting a low energy gap (ΔE = 5.236 eV), high dipole moment, and electronic features conducive to strong interaction with the metal surface. Surface imaging by SEM further demonstrated formation of a protective barrier on the steel surface.

Keywords

Main Subjects

Progress in Color, Colorants and Coatings

Articles in Press, Accepted Manuscript
Available Online from 16 May 2026

Files

Share

How to cite

Statistics