Investigation of a Pharmaceutically Active Compound Omeprazole as Inhibitor for Corrosion of Mild Steel in H₂SO₄ Solution

摘要

Inhibition performance of omeprazole for mild steel in 0.1M H2SO4 solution has been investigatedthrough different approaches including potentiodynamic polarization, electrochemical impedancespectroscopy (EIS), weight loss, scanning electron microscope (SEM) experiments and theoreticalcalculations. The experimental results reveal that omeprazole is an effective inhibitor with a maximumachievable inhibition efficiency of 98.5%, and the adsorption of omeprazole on the mild steel surfaceis found to obey the Langmuir adsorption isotherm. Polarization curves illustrate that omeprazole actsas a mixed-type inhibitor, and EIS demonstrates that an adsorption film of the inhibitor is formed onmild steel surface. Moreover, quantum chemical calculations and the molecular dynamics (MD)simulation are also performed to gain the further insight of the inhibition mechanism of omeprazole onsteel corrosion, which show that the possible adsorption centers of the omeprazole molecule arebenzene ring, benzimidazole ring, sulphinyl and the nitrogen atom of the hexaheterocyclic.