Anticorrosive properties of aqueous Cichorium intybus seeds extract as a sustainable-green inhibitor for aluminum corrosion in hydrochloric acid solution: An experimental and DFT/MC/MD theoretical approach

Abstract

The inhibitory effect of Cichorium intybus seeds (C. Intybus) on the corrosion behavior of Al 7075 alloy was evaluated in a 1 M HCl acid solution using chemical and electrochemical methods. The adsorption process was proved using FTIR, UV-Vis, Fluorescence, SEM, EDX, AFM, and contact angle measurements. The results reflect that C. Intybus provided excellent protection, and all measurements showed that the inhibition performance of extracts increased by increasing the concentration to reach 93.67% at 12% v/v. Furthermore, this substance functioned as a mixed-type inhibitor to obstruct the anodic and cathodic active sites on the surface of the metal. The study outcomes matched the monolayer Langmuir isotherm, and the calculated adsorption free energy and activation energy reflect that the inhibition mechanism featured the physisorption process. The computational studies were used to provide further confirmation of the adsorption mechanism and to find out how organic inhibitor molecules interact with metal surface using Density Functional Theory (DFT) with Lee/Yang/Parr (B3LYP) level, 6–311 + + G(d,p) as the basis function set calculation, Monte Carlo (MC), and Molecular Dynamic (MD) simulations. The findings showed good agreement with both the experimental and theoretical results. One of the important findings of this work is the possibility of using C. Intybus as a greener alternative and environmentally friendly resource for corrosion inhibition in an acidic medium.