Experimental studies of 2-pyridinecarbonitrile as corrosion inhibitor for mild steel in hydrochloric acid solution

The effect of 2-Pyridinecarbonitrile (2-PCN) was studied on mild steel (MS) corrosion in 0.1 mol L−1 HCl by electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and potentiodynamic polarization measurements. The surface morphologies of the MS were investigated in the inhibitor-free and in the presence of 10 mmol L−1 2-PCN containing corrosive media, at 120 h exposure period by scanning electron microscopy (SEM). The mechanism of adsorption was determined from the potential of zero charge (Epzc). 2-PCN adsorption on the MS surface obeyed the isotherm of Langmuir and the thermodynamic parameters Kads; ΔGads° were also calculated and discussed.