Aqueous Extracts of Aaronsohnia pubescens subsp. pubescens Aerial Parts as Green Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

Abstract

In this study, two aqueous extracts from the aerial parts of Aaronsohnia pubescens subsp.pubescens (Odorized aqueous extract (OE) and Deodorized aqueous extract (DE)) were used as somenovel ecological corrosion inhibitors for mild steel (MS) in 1 M HCl medium. For this reason, theinhibition behavior of the OE and DE were investigated using weight loss measurements, electrochemicalassays, kinetics, and thermodynamic parameters, and electrochemical methods, both stationary(Potentiodynamic polarization (PDP)) and transient (Electrochemical impedance spectroscopy (EIS)).The obtained results showed that EO and DE act as effective corrosion inhibitors and the inhibitionefficiency of inhibitors increases for the concentration of 1.5 g/L; reaching some high values of 93.11and 87.88% in 1 M HCl solution at 308 K for OE and DE, respectively. Furthermore, PDP measurementsexhibited that the studied of each inhibitor performs as a mixed-type inhibitor. The results of thethermodynamic kinetic parameters indicate the adsorption of OE and DE on the MS surface sites obeyingthe Langmuir adsorption isotherm.