Aqueous Extract of Juniperus as a Green Corrosion Inhibitor for Mild Steel (MS) in Sulfamic Acid (NH2SO3H) Solutions

Abstract

The corrosion behavior of mild steel (MS) in 5% NH₂SO₃H solution in the nonexistence and existence of aqueous extract of Juniperus was investigated using mass loss (ML), potentiostatic polarization (PP), AC electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) techniques. It was found that, the inhibition efficiency (P%) of this plant extract depends on its concentration and temperature. Polarization studies revealed that this extract behaved as mixed-type inhibitor. The adsorption process was found to follow Langmuir adsorption isotherm. The effect of temperature on the rate of corrosion in the nonexistence and existence of this extract was also, studied and some activation and adsorption thermodynamic parameters were computed and discussed. The inhibitive action of the investigated extract was discussed in terms of blocking the electrode surface by adsorption of its active molecules through the active centers contained in their structures.