Evaluation of Trimethoprim Drug as a Green Corrosion Inhibitor for Mild Steel in 1.0 M Sulfuric Acid

The mitigation of mild steel corrosion in 1.0 M H2SO4 solution by trimethoprim drug as a green and commercially available inhibitor was studied at room temperature using weight loss, open circuit potential, and potentiodynamic polarization techniques. The results showed that the investigated compound's inhibition efficiency depended on the concentration and nature of the inhibitor. The inhibition efficiency was found to increase with the concentration of the inhibitor. The polarization result indicated that the compound behaved as mix type inhibitor. The inhibition is assumed to occur via physical adsorption of inhibitor on the metal surface, which obeyed Langmuir adsorption isotherm. The scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDX) results confirmed the formation of a protective layer on the mild steel surface.