Evaluation of Lavandula mairei extract as green inhibitor for mild steel corrosion in 1 M HCl solution. Experimental and theoretical approach

Corrosion inhibition of mild steel sample in hydrochloric acid solution was examined via weight loss and electrochemical measurements, Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) techniques. The use of Lavandula mairei Humbert extract (LM) as an eco-friendly inhibitor of mild steel (MS) corrosion in 1 M HCl solution has significantly decreased MS corrosion rate. The corrosion inhibition efficiency increased with the increase of LM concentration up to 92% obtained at 303 K for a 0.4 g/ L concentration. The adsorption of LM inhibitor on the mild steel surface followed the Langmuir adsorption isotherm. Anodic Tafel slope digression and continuous CR lessening with the LM extract concentration increase, has validated the limited dissolution of mild steel. Theoretical approaches based on chemical quantum calculations and molecular dynamics simulation clearly explains the mode of adsorption of the majority molecule on the metal surface. (C) 2020 Elsevier B.V. All rights reserved.