Experimental and theoretical studies of the inhibition performance of two furan derivatives on mild steel corrosion in acidic medium

Abstract

Inhibition performance of 2‐furanmethanethiol (FMT) and 2‐furonitrile (FN) against mild steel corrosion in 1 M hydrochloric acid was investigated using weight loss, adsorption isotherms, and electrochemical impedance spectroscopy (EIS). The surface morphology was studied by field emission scanning electron microscope (FESEM) and X‐ray photoelectron spectroscopy (XPS). Quantum chemical calculations were carried out to establish the active sites on the inhibitors. The results show that both inhibitors inhibit mild steel corrosion, and their inhibition efficiencies (IE) increase with increasing inhibitor concentration. FMT shows higher inhibiting effect with IE of 94.54% at 0.005 M. The adsorption of the inhibitors onto mild steel surface obeys Langmuir isotherm. FESEM analysis confirms the adsorption of both inhibitors on the surface. XPS analysis proves the adsorption of FMT onto the surface. The active sites on FMT and FN molecules were effectively established using density functional theory (DFT) based on natural atomic charge, Fukui indices, HOMO and LUMO frontier molecular orbitals. The experimental and quantum results prove the inhibition performances of both inhibitors. FMT performs as an efficient inhibitor with a significant and higher IE compared to FN.