DFT Study on Corrosion Inhibition by Tetrazole Derivatives: Investigation of the Substitution Effect

Corrosion is one of the problems that most industries face. Our aim in the current study is to perform density functional theory calculations and Monte Carlo simulation to theoretically investigate the corrosion inhibition of the copper (1 1 1) surface by tetrazole molecules and a group of their derivatives. These compounds have electron-donating groups (CH₃, CH₃O, and OH) and electron-withdrawing groups (F, CN, and NO₂). Two different isomeric forms of tetrazole molecules and their derivatives, including 1H and 2H tautomers, were studied in two configurations, parallel and perpendicular to the Cu (1 1 1) surface. With the help of DMol3 calculations, the most important parameters related to the molecular ability of tetrazole derivatives as corrosion inhibitors include the adsorption energy (ΔE), E _HOMO, E _LUMO, E _gap, and issues related to chemical reactions, including total hardness (η), electronegativity (χ), and electron fraction transitions from the anti-corrosion molecule to the copper atom (ΔN), were calculated and compared in the tetrazole molecules and their derivatives. Also, with the help of adsorption locator calculations, the inhibitory effects of these compounds were theoretically investigated in an acidic environment. Through these calculations, it was determined that tetrazole molecules with electron-donating groups adsorbed perpendicularly to the copper (1 1 1) surface, by forming a stronger bond, are considered suitable corrosion inhibitors. Also, among the examined molecules, the 2H-tetrazole isomer form plays a more influential role than the 1H-tetrazole form.