Establishment of Electrical Equivalent Circuits from electrochemical impedance spectroscopy study of corrosion inhibition of steel by imidazolium derived ionic liquids in sulphuric acidic solution

This paper describes the use of the electrochemical impedance spectroscopy technique (EIS) in order to establish Electrical Equivalent Circuits to study the corrosion inhibition process of steel in 1.0 M H₂SO₄ solution at the open circuit potential (OCP). Two ionic liquids derived of Imidazolium with different alkyl chain long, known as Long Chain (LC) and Short Chain (SC), as corrosion inhibitor has been examined. The Nyquist diagrams consisted of a capacitive semicircle at high frequencies followed by a well-defined inductive loop at low frequency values. The impedance measurements were interpreted according to suitable equivalent circuits.