Enhancing Corrosion Resistance of Carbon Steel in Sulfuric Acid Using β-cyclodextrin as an Inhibitor

Abstract

The corrosion process leads to substantial economic losses, particularly in the industrial sector, emphasizing the importance of preventive measures. This study aimed to investigate the impact of inhibitor concentration, immersion duration, and temperature on the corrosion of carbon steel in a sulfuric acid environment, assessed through mass loss measurements. Inhibition efficiency displayed a positive correlation with increasing inhibitor concentration, while it declined as temperatures rose. In a 0.5 M sulfuric acid solution, β-cyclodextrin (β-CD) exhibited an inhibition efficiency of 62.26% at a concentration of 1 mM. The addition of potassium iodide (KI) significantly enhanced the inhibition efficiency to 97.98%, indicating a synergistic effect. The study encompassed various calculations, including the determination of activation energy (Ea), activation enthalpy (ΔHa), activation entropy (ΔSa), adsorption-free energy (ΔGads), adsorption enthalpy (ΔHads), and adsorption entropy (ΔSads). The adsorption of the inhibitor onto the carbon steel surface conformed to the Langmuir adsorption isotherm. Additionally, Scanning Electron Microscopy (SEM) investigations provided further verification of β-cyclodextrin's adsorption on the carbon steel surface.