Electrochemical, AFM Surface, and Computational Assessment of Melochia corchorifolia Extract as an Eco‐Friendly Corrosion Inhibitor for Mild Steel in 0.5 M Hydrochloric Acid

ABSTRACT

This research explores the corrosion‐resistant tendencies of Melochia corchorifolia extract (MCE) for mild steel in 0.5 M HCl. This study aims to provide a sustainable yet effective solution to corrosion issues by using of MCE acting as a substitute for conventional synthetic corrosion inhibitors. The corrosion inhibition effectiveness of the MCE was estimated utilizing a number of approaches. MCE had a maximal inhibitory efficiency of 95.03% in potentiodynamic polarization experiments at an optimal concentration of 100 mg L ⁻¹ . The charge transfer resistance increased from 5.097 to 162.18 Ώ cm ² , yet the corrosion current density reduced dramatically. Along with weight loss studies, the surface analysis was carried with scanning electron microscopy (SEM), and the MCE adsorption on the mild steel surface was evidenced. AFM research revealed that the average surface roughness dropped from 326 to 45 nm after treatment with inhibited solution, indicating the presence of an adsorbed protective coating. The density functional theory (DFT) investigation testifies to the potency of MCE as an anticorrosion agent.