Corrosion prevention of AISI 304 stainless steel in hydrochloric acid medium using garlic extract as a green corrosion inhibitor: Electrochemical and theoretical studies

The presence of various functional groups in the primary molecules of the garlic extract makes this extract a suitable candidate for corrosion inhibition of AISI 304 stainless steel in acidic electrolytes. In this study, corrosion of AISI 304 stainless steel in 0.5 M HCl in the presence of the garlic extract was investigated using weight loss measurement, potentiodynamic polarization, electrochemical noise analysis, and computational simulation including density functional theory (DFT), Monte Carlo (MC), and molecular dynamics (MD). The results from the weight loss and electrochemical measurements indicated that the garlic extract reduces the corrosion rate of the stainless steel in Ha solution up to 88%, and the extract works as a mixed type corrosion inhibitor by hindering both cathodic and anodic reactions on the surface. Further investigation illustrated that the inhibitor follows the Langmuir adsorption isotherm during the process of adsorption. Moreover, the computational findings from DFT modeling and molecular simulations based on MC and MD shed more light on the surface adsorption features of the garlic extract. (C) 2020 Elsevier B.V. All rights reserved.