Electrochemical study and molecular dynamics (MD) simulation of aluminum in the presence of garlic extract as a green inhibitor

The aim of this study was to investigate the effect of garlic extract as a green inhibitor on the uniform and localized corrosion of 1050 aluminum alloy in aerated 3.5 wt% NaCl solution. In this regard, electrochemical methods such as linear polarization, electrochemical impedance spectroscopy (EIS), and electrochemical noise analysis (EN), were carried out to study the corrosion behavior. The theoretical approaches based on molecular dynamics simulation were also applied to obtain precise insight into the interfacial interactions and adsorption mechanism. EN measurements revealed that the addition of garlic extract increases the pit initiation rate by forming an antioxidant layer on the Al surface. However, the extract's chemical adsorption enhances over time, thereby the propagation of corrosion damage reduces up to one-tenth. EIS results showed that, the garlic extract with 8 mL.L-1 concentration induces the most effective inhibition by enhancing the corrosion resistance from 2917 Omega.cm(2) to 14,557 Omega.cm(2). The outcomes of MD simulation indicated that the pyridoxal phosphate has not only the parallel adsorption on the surface but also the most negative bonding energy. These phenomena are the factors behind the anticorrosive behavior of garlic extract on the Al surface. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study found that garlic extract, as a corrosion inhibitor, can form an antioxidant layer on the aluminum surface, increasing pit initiation rate, but decreasing corrosion damage propagation over time; garlic extract at a concentration of 8 mL.L-1 showed the most effective enhancement of corrosion resistance.