Unlocking the power of Inula Viscosa essential oil: A green solution for corrosion inhibition in XC48 steel within acidic environments

Abstract

A sustainable corrosion inhibitor for XC48 steel in a 1 M HCl environment was effectively formulated using the essential oil of Inula viscosa (IVEO), as corroborated by gas chromatography-mass spectrometry (GC-MS) results. This novel application was assessed via multiple techniques: mass loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), Fourier-transform infrared spectroscopy with an attenuated total reflectance accessory (FT-IR/ATR), X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and Atomic Force Microscopy (AFM) for surface examination. The plant extract’s inhibitory capacity raised in proportion to its concentration, as confirmed by both mass loss and electrochemical investigations. This trend reached a high point at a 97% inhibitory efficiency at a concentration of 400 ppm at 298 K. FTIR, XRD, SEM/EDS, and AFM analyses further validated the binding of this eco-friendly inhibitor onto the steel surface, which exhibited mixed-type characteristics, thus elucidating its exceptional inhibitory performance. The Langmuir isotherm model aptly fitted the adsorption analysis, indicating the development of an organic protective layer. Advances computational calculations of various quantum chemical parameters for the key ingredients of the essential oil added to the understanding of the link between adsorption and corrosion inhibition.