Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Solution Using a Sulfa Drug

The corrosion inhibition of carbon steel in 1.0 mol L HCl in the presence of an antibacterial sulfa drug Sulfathiazole, IUPAC name 4-amino-N-(1,3-thiazol-2-yl) benzene sulfonamide (TBSA) was investigated using mass loss and electrochemical measurements such as: potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Surface chemistry was analyzed by X-ray photoelectron spectroscopy (XPS). For the study of the surface morphology scanning electron spectroscopy (SEM) was used. The results showed that TBSA acts as a corrosion inhibitor in 1.0 mol L HCl solution by suppressing simultaneously the cathodic and anodic processes via adsorption on the carbon steel surface and that the inhibition efficiency increases with increasing concentration. XPS analysis revealed that the corrosion product consists of an oxyhydroxide/oxide mixture and that the iron oxyhydroxide proportion is higher than the iron oxide proportion.