2024/01/25 by Kilo, Mohamad, Saad, Ibtissam, Younes, Ghassan +1
#Adsorption isotherms #EIS #FTIR #Potentiodynamic Polarization #TCC #TFC #TPC
paper · doi:10.48317/imist.prsm/morjchem-v12i2.45865
The anticorrosion characteristics of Phaseolus vulgaris L. aqueous leaves extract were examined for the protection of carbon steel in 0.5 M sulfuric acid and 0.5 M phosphoric acid solutions using potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS). The extract acted as mixed-type inhibitor, and was more potent in H3PO4 than in H2SO4. The adsorption of the extract on the metal surface obeyed Flory–Huggins, Temkin, and the Kinetic-Thermodynamic isotherms but not the Langmuir model. Analysis of the thermodynamic and activation parameters suggested that physical adsorption governed the inhibition mechanism. The total phenolic, total flavonoid, total carbohydrates, and protein contents in the extract were 121.80 ± 3.65 mg GAE/g DW, 67.65 ± 2.31 mg RE/g DW, 2.67 ± 0.32 mg GE/g DW, and 0.122%, respectively. The richness of the extract in phenolic compounds justified the strong adsorption of the P. vulgaris phytochemicals onto the surface of the metal.