Armoracia rusticana as sustainable and eco-friendly corrosion inhibitor for mild steel in 0.5M sulphuric acid: Experimental and theoretical investigations

Abstract The current investigation presents the corrosion activity of Armoracia rusticana root extract in 0.5 M H 2 SO 4 as a corrosive medium. This plant belongs to the Brassicaceae family. Weight loss measurements, Tafel polarization and electrochemical impedance spectroscopy (EIS) measurements have been done to check the inhibition efficiency. Ultraviolet-visible (UV), Fourier-transform infrared (FT-IR) spectroscopic techniques have been carried out to verify the adsorption phenomenon and functional groups in the plant extract. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques have been conducted for surface investigation of exposed mild steel. The synergism studies and theoretical calculations have been done using HyperChem 8.0 program. Electrochemical examination and weight reduction estimations say that the root extract for Armoracia rusticana indicates the amazing inhibition efficiency up to 95.74% for mild steel at 100 mg/L concentration in 0.5 M H 2 SO 4 solution at 298 K. The adsorption of the inhibitor obeys the Langmuir adsorption isotherm.