Corrosion inhibition performance of carbon steel in sulfuric acid using gum arabic extract: experimental insights, DFT analysis, and molecular dynamics simulations
Mardali Yousefpour, Reza zahed Shayegh, Amir Hossein Hafazeh, Hossein Tavakoli
Abstract
• Gum Arabic extract achieves 84 % corrosion inhibition for carbon steel in 1 M H 2 SO 4 . • Mixed-type inhibition confirmed via electrochemical and surface analyses. • MD and quantum studies show spontaneous adsorption, forming a protective film. • Eco-friendly, sustainable inhibitor for industrial acidic applications. Corrosion of carbon steel in acidic environments poses a significant challenge in industrial applications, driving the need for eco-friendly and efficient corrosion inhibitors. This study investigates the potential of Gum Arabic (GA) extract as a green inhibitor to mitigate carbon steel corrosion in an acidic medium through a combined experimental and computational approach. Potentiodynamic polarization (PDP) analyses demonstrated that GA extract attains an inhibition efficiency of about 83 % at 1000 ppm, whereas electrochemical impedance spectroscopy (EIS) validated a marginally higher efficiency of 84 % at the identical concentration. These results indicate GA’s strong protective capability, likely due to its adsorption onto the steel surface. Molecular dynamics (MD) simulations further elucidated the inhibition mechanism, demonstrating a favorable adsorption energy of -16.6 kJ/mol, suggestive of a spontaneous and stable interaction between GA molecules and the carbon steel surface. The MD simulations validated the experimental results, confirming the adsorption-driven inhibition mechanism of GA on the carbon steel surface. Surface characterizations and electrochemical results jointly highlight the development of a shielding film that reduces corrosion under harsh acidic environments. This work advances the understanding of natural inhibitors and offers a promising green solution for corrosion control.