Toward understanding the anticorrosive mechanism of some thiourea derivatives for carbon steel corrosion: A combined DFT and molecular dynamics investigation

Abstract

The mutually corroborated density functional theory (DFT) and molecular dynamics (MD) simulation methodology were employed to evaluate the inhibition performance of three thiourea derivatives (Inh1, Inh2, and Inh3) on carbon steel corrosion. Experimental results have shown that the corrosion rate follows the order: Inh3>Inh2>Inh1. Quantum chemical descriptors such as the frontier orbital energies (E_HOMO and E_LUMO), the energy gap between E_LUMO and E_HOMO (ΔE), dipole moment (μ), and Fukui index have been calculated and discussed. Some significant factors such as solvent, temperature, and coverage have been considered when investigating the adsorption of aforementioned thiourea derivatives on Fe(110) surface. Our results provide important atomic/molecular insights into the anticorrosive mechanism of inhibitor molecules, which could help in understanding the organic-metal interface and designing more appropriate organic corrosion inhibitors.

Keywords: Carbon steel; Corrosion inhibitor; DFT; Molecular dynamics; Thiourea derivative.