Investigating the Effectiveness of an Imidazopyridine-Based Compound as an Anti-corrosive Additive for Mild Steel in Molar Hydrochloric Solutions: A Mutual Multi-Facet Experimental and Computational Approach

The use of effective, environmentally friendly inhibitors is a promising strategy to mitigate metallic corrosion. This work involved the development of a newly developed imidazopyridine-based compound (i.e., MPPIP) and an assessment of its effectiveness as an anti-corrosive entity for the mild steel metal (MS) in 1.00M hydrochloric medium. The compound’s performance was evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), which demonstrated that MPPIP achieves 98% inhibition efficiency with 10⁻³ M concentration at the room temperature. The electrochemical analysis confirmed that MPPIP acts as a mixed-type inhibitor, reducing both anodic and cathodic reactions. Thermodynamic analyses revealed that MPPIP adsorption follows the Langmuir’s isotherm, involving a combination of physisorption and chemisorption mechanisms. Additional validation was performed using UV-Vis. spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), which revealed a uniform protective film on the steel surface, preventing metal dissolution. Computational approaches, including density functional theory (DFT) and Monte Carlo simulations, highlighted the molecule’s high electron-donating ability and strong adsorption energy, confirming its strong interaction with the metal surface. These findings demonstrate that MPPIP is a promising and efficient corrosion inhibitor for mild steel in acidic environments with an inexpensive and easily synthesized route characteristics.