A comparative DFT investigation of the corrosion inhibition performance of carbohydrate-based mono- and disaccharide derivatives on Al(111)

Carbohydrate derivatives representing different structural categories such as open-chain monosaccharides (glucose and fructose), cyclic monosaccharides (D-glucose, D-β-fructofuranose, and D-galactose), and disaccharides (sucrose, maltose, and β-lactose) were examined as potential eco-friendly corrosion inhibitors on the Al(111) surface, using Density Functional Theory (DFT) to identify and compare their inhibition efficiency and adsorption behavior. A combination of quantum chemical descriptors derived from DFT and periodic DFT calculations (PBC-DFT), aimed at elucidating the corrosion inhibition mechanism on the Al(111) surface. The results demonstrate that sucrose and β-lactose exhibit the highest adsorption energies, at −46.197 and −44.561 kcal/mol, respectively, compared to their analogues. In addition, glucose (OC), fructose (OC), sucrose, maltose, and β-lactose adsorb onto the Al(111) surface via coordinate covalent O–Al bond formation, indicating chemisorption as the predominant adsorption mechanism. In contrast, the cyclic monosaccharides D-glucose, D-β-fructofuranose, and D-galactose adsorb onto the Al(111) surface without forming covalent bonds, suggesting that the adsorption process is governed by physisorption rather than chemisorption.