Theoretical and experimental inhibitive properties of mild steel in HCl by ethanolic extract of Boscia senegalensis

The experimental aspect of the corrosion inhibition potentials of Boscia senegalensis was carried out using gravimetric and linear polarization techniques as well as scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR), whereas the theoretical aspect was studied using the density functional theory calculations to be performed and modeling the electronic structures of some extract constituents, including physiosorptive interactions with the Fe surface. The analyses of the experimental results showed that the inhibition efficiency increased with increase in concentration of the inhibitor and decreased with increase in temperature. The efficiency of the extract in HCl was 70%. Thermodynamic parameters revealed that the adsorption of extract onto the metal surface was spontaneous, exothermic, and supported the physical adsorption process. FTIR results showed that the inhibition mechanism was an absorption process through the functional groups present in the extract and that of the inhibited. Surface morphology also revealed that corrosion product confirmed the protection offered by the extract on the surface of the metal immersed in the acid media. The data obtained were fitted into various adsorption isotherms, though the Freundlich isotherm was found to be the best fit.