Corrosion inhibition of mild steel in acidic media using benzimidazolium salts: An experimental and computational approach

This study investigates and compares the corrosion inhibition performance of two benzimidazolium salts (BIS1 and BIS2), previously synthesized by Albayrak et al. and Sar & imath; et al., respectively. These inhibitors were tested in a 1 M hydrochloric acid solution on mild steel. The two compounds differ in their substituents: BIS1 features an electron-donating group, whereas BIS2 contains an electron-accepting substituent. Electrochemical methods, including potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and weight-loss measurements, consistently demonstrated superior inhibition efficiency for BIS1, exceeding 95 % at 10-3 M concentration. The performance disparity between BIS1 and BIS2 further increased with rising temperatures. Surface characterization by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX), atomic force microscopy (AFM), and X-ray Photoelectron Spectroscopy revealed that BIS1 forms a denser and more adherent protective film on the steel surface. Molecular modeling techniques, including Density Functional Theory (DFT), Tight-binding DFT (DFTB), and Molecular Dynamics (MD) simulations, provided further insights, showing that the enhanced performance of BIS1 is primarily attributed to its higher HOMO energy, facilitating stronger chemisorption via electron donation to the metal surface. These findings challenge the conventional understanding of purely electrostatic adsorption for cationic inhibitors and underscore the significant potential of substituted benzimidazolium salts as efficient corrosion inhibitors.

Dergi

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

Yıl

2025

Cilt

726

ISSN

0927-7757

eISSN

1873-4359

DOI

10.1016/j.colsurfa.2025.137815

WoS UID

WOS:001543363100002