Computational analysis of the corrosion inhibition potential of isovitexin: A combined DFT and MD simulation study on aluminum alloy protection.

In this study, Density Functional Theory (DFT), Molecular Dynamics (MD) simulations, Natural Bond Orbital (NBO), and topological analyses were employed to evaluate the corrosion inhibition performance of isovitexin on AA2024 aluminum alloy in acidic media. Quantum chemical calculations revealed that neutral isovitexin exhibits superior inhibition potential compared to its protonated form, as evidenced by its lower HOMO-LUMO energy gap (ΔE = 0.482 eV), higher softness (σ = 4.15 eV-1), lower global hardness (η = 0.241 eV), and greater electron-transfer capability. MD simulations demonstrated strong and spontaneous adsorption of isovitexin on the AA2024 surface, with a highly negative interaction energy of -130 kcal mol-1 and a binding energy of 130 kcal mol-1, significantly greater than those obtained for the protonated form (-85 and 85 kcal mol-1, respectively). These findings indicate the formation of a stable and compact protective film on the metal surface. Furthermore, topological analysis confirmed that adsorption is stabilized through a synergistic combination of van der Waals interactions, hydrogen bonding, and donor-acceptor interactions. Collectively, the electronic, adsorption, and charge-transfer analyses establish isovitexin as a promising eco-friendly corrosion inhibitor, capable of providing efficient protection of aluminum alloys in acidic environments through strong surface adsorption and favorable molecular interaction characteristics.