The Penicillin Derivatives as Corrosion Inhibitors for Mild Steel in Hydrochloric Acid Solution: Experimental and Theoretical Studies

Abstract

The inhibition performances of four penicillin derivatives, including penicillin G, oxacillin, penicillin V and amoxicillin as organic corrosion inhibitors for mild steel in 1.0 M HCl solution were investigated by weight loss measurement and Tafel polarization technique. The electrochemical results reveal that the four penicillin derivatives are qualified, mix-type corrosion inhibitors, and the inhibition efficiency follow the order: oxacillin>amoxicillin>penicillin V>penicillin G. The results obtained from electrochemical and weight loss studies are in reasonable agreement. Quantum chemical calculation was used to correlate inhibition abilities with their electronic structural parameters. In addition, the molecular dynamics simulations were employed to get insight into the equilibrium adsorption configurations and calculate the binding energy between the inhibitors and iron surface. Theoretical calculations support the experimental results and elucidate working mechanisms.