The Synergistic Impact of the Aqueous Valerian Extract and Zinc Ions for the Corrosion Protection of Mild Steel in Acidic Environment

Abstract

Abstract Herein, the corrosion inhibition performance of mild steel (MS) in an acidic environment (1.0 M HCl) by the valerian extract has been studied via weight loss method (WL), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The results illustrated that the inhibition efficiency, raised by the rise of the extract concentrations. The inhibitory mechanism depended on the creation of a stable plant extract-complex on the mild steel surface. Polarization studies confirmed that the extract behaved as a mixed type inhibitor. The corrosion inhibition was supposed to exist via adsorption of the main components of the valerian extract. Attenuated total reflection-infrared spectroscopy (ATR-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to investigate the change in the surface morphology and confirmed the corrosion inhibition mechanism. The complete study confirmed that the efficiency of the valerian extract as a safe, eco-friendly and exchange corrosion inhibition for mild steel in an acidic environment.