Adsorption and Corrosion Inhibition Behaviour of Oil Extracted from Moringa peregrina leaves for Carbon Steel in Acidic Media: Experimental and Computational Studies

Abstract

The current research aimed at investigating the potential corrosion inhibitory effect of essential oil extracted from Moringa peregrina leaves on carbon steel in acidic conditions. Gas chromatography (GC) and scanning electron microscope (SEM) were employed for studying the composition of the inhibitor and surface morphological changes of CS samples. Different experimental techniques such as chemical, electrochemical and surface characterization techniques were utilized for carbon steel (CS) immersed in 1.0 M HCl solution. Experimental observations suggest that through physical and chemical interactions, the inhibitor molecules form a stable layer on steel surface. The nature of adsorption of the investigated inhibitor onto the carbon steel surface obeyed the Langmuir isotherm model. Moreover, the electrochemical results revealed that the investigated inhibitor acts as a mixedtype inhibitor. Density function theory (DFT) calculations and molecular dynamic (MD) simulations were utilized to gain an insight into the possible interactions between the carbon steel surface and the inhibitor molecule mainly 9-Octadecadienoic acid (Z) present in the essential oil.