Green Corrosion Inhibition of Mild Steel in 1.0 M HCl Using Myrtus Communis Essential Oil: Experimental and Theoretical Investigations

Abstract

This study investigates the green corrosion inhibition of mild steel in 1.0 M HCl using Myrtus communis essential oil (EOMC). Experimental and computational methods were combined to evaluate the corrosion inhibition effectiveness of EOMC. Weight loss measurements and electrochemical techniques, demonstrated that EOMC achieves a maximum corrosion inhibition efficiency of 94.81% at a concentration of 400 ppm of MCEO extract. The icorr significantly decreased from 983 µA/cm2 in the 1.0 M HCl solution to 51 µA/cm2 at 10−3 M, demonstrating the inhibitor's effectiveness. Polarization studies suggested mixed‐type inhibition, affecting both anodic and cathodic reactions, supported by changes in Tafel slopes. The Rct reached 462 Ω cm2 at 400 ppm of EOMC, enhancing the steel's protective capability. Higher temperatures increased the corrosion rate, with icorr values rising from 51 µA/cm2 at 298 K to 501 µA/cm2. Surface analysis using scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (SEM‐EDX) confirmed the formation of a protective layer on the steel surface in the presence of EOMC. Additionally, density functional theory (DFT) calculations and molecular dynamics (MD) simulations provided further insights into the adsorption behavior of the EOMC molecules on the MS surface, revealing that the inhibition process involves both physisorption and chemisorption mechanisms.