Adsorption and corrosion-inhibiting effect of Dacryodis edulis extract on low-carbon-steel corrosion in acidic media

The inhibition of low-carbon-steel corrosion in 1 M HCl and 0.5 M H2SO4 by extracts of Dacryodis edulis (DE) was investigated using gravimetric and electrochemical techniques. DE extract was found to inhibit the uniform and localized corrosion of carbon steel in the acidic media, affecting both the cathodic and anodic partial reactions. The corrosion process was inhibited by adsorption of the extracted organic matter onto the steel surface in a concentration-dependent manner and involved both protonated and molecular species. Molecular dynamics simulations were performed to illustrate the process of adsorption of some specific components of the extract.

Dacryodis edulis extract was studied as a corrosion inhibitor for mild steel in acidic media. The electronic structures of the extract components (A) ascorbic acid, (B) β-caryophyllene and (C) an alkaloid (HBMB) show that the molecules could be adsorbed on the corroding metal surface, and thus retard the corrosion reaction.Figure optionsDownload high-quality image (35 K)Download as PowerPoint slideResearch highlights
► The absorbed organic constituents inhibit corrosion.
► Inhibiting effects of the different extract constituents vary randomly.
► Their individual effects depend on envirionmental conditions.