Inhibitory Action of Funtumia elastica Extracts on the Corrosion of Q235 Mild Steel in Hydrochloric Acid Medium: Experimental and Theoretical Studies

Abstract

The inhibiting effect of aqueous extracts of Funtumia elastica (FE) on mild steel corrosion in 1 M HCl solution was investigated using electrochemical and surface characterization techniques. The results revealed that FE effectively inhibited the corrosion reaction. Polarization data reveal that the extract functioned as a mixed-type inhibitor, while impedance results show that the extract organic matter gets adsorbed on the metal/solution interface. Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy results confirmed the formation of a protective layer of extract adsorbed on the mild steel surface. Adsorption of some organic constituents of FE on mild steel was theoretically described by quantum chemical computations and molecular dynamics simulations, in the framework of the density functional theory.

GRAPHICAL ABSTRACT

Keywords:

• Corrosion
• inhibition
• mild steel
• polarization
• scanning electron microscopy