The current investigation studies the anticorrosion properties of mild steel (MS) samples in an HCl medium using bio-inhibitors obtained from the Cinnamomum cassia plant.Firstly, the d. functional theory was conducted to evaluate the reactivity of the Cinnamomum cassia plant's principal components.Thus, MCE and ACE extracts were prepared from the methanolic and ethanolic solvents.Therefore, phytochem. screening and Fourier transform IR confirmed their secondary metabolite matched.Then, the anticorrosion property was examined using weight loss (WL%) and electrochem. techniques (PP-EIS).The obtained results showed good inhibition behavior, yielding a maximum of 96% for MCE and 94% for ACE extracts at a concentration of 1 g.L-1; and their adsorption to the metal surface follows the Langmuir isotherm model and involved a physisorption mode.While, polarization studies showed that these extracts behave as a mixed type inhibitors.This finding was verified by the adsorption of the extract component structures on the sample's surface, confirmed by SEM-EDX anal.In addition, the UV-visible spectroscopy anal. confirms the interaction occurs between iron atoms and the extract constituents.Furthermore, in order to better understand the inhibition mechanism of the said extracts against corrosion of the tested steel, and to validate the exptl. results, DFT were carried out.
