Syzygium cumini leaf extract as an eco-friendly corrosion inhibitor for carbon steel in acidic medium

Abstract

The efficiency of Syzygium cumini leaf extract (SCLE) as a corrosion inhibitor was evaluated for carbon steel in 0.5 mol L−1 H2SO4 by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) measurements. It was clearly demonstrated that the inhibition efficiency increased with increasing concentration of leaf extract, due to a decrease in the cathodic currents and blocking of the active corroding sites. The presence of organic molecules from the SCLE on the carbon steel surface was confirmed by FT-IR spectroscopy. The adsorption of species on the alloy surface was modeled using the Langmuir isotherm. A decrease in the carbon steel acid corrosion in the presence of SCLE was also confirmed through contact angle measurements and scanning electron microscopy (SEM).