Inhibition of Copper Corrosion in Acid Medium by Imidazole-Based Compounds: Electrochemical and Molecular Approaches

Abstract

Chemically modified imidazole molecules: 4-(1H-imidazol-1-yl)aniline, 4-(1H-imidazol1-yl)benzaldehyde, 4-(1H-imidazol-1-yl)phenol and (4-(1H-imidazol-1-yl)phenyl)methanol were investigated as inhibitors of the copper (Cu0) corrosion in 0.5 mol L-1 H2SO4 medium. The electrochemical corrosion data were obtained by monitoring open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy techniques, while the computational density functional theory (DFT) method was applied to correlate the electronic properties of the molecules with corrosion inhibition efficiencies. All molecules had inhibited the Cu corrosion, and the inhibition values lied between 80 and 94%. A good correlation between the inhibition efficiencies values and Gibbs adsorption energy was found, showing that the more negative Gibbs energy, better interaction between the corrosion inhibitor with the Cu0 surface, diminishing its corrosion in 0.5 mol L-1 H2SO4 medium. The DFT calculations showed significative differences in electronic and reactivity properties of imidazole and other molecules. The higher corrosion inhibition of imidazole derivates could be explained by electrophilic characteristic of these molecules, since there are empty molecular orbitals spread over mainly in benzene rings that make a metal-ligand charge transfer, receiving electronic density from the copper surface by backbonding, according to the electronic Fukui functions and the potential charge distribution considering the map of electrostatic potential.

Nitrogen–Sulfur Codoped Ti3C2Tx MXene as a Corrosion Inhibitor for Copper in a Chloride Environment: Electrochemical and Computational Studies

“…Figure a describes the OCP time plot for Cu in chloride solution and with varying inhibitors for 1 h. As presented, a negative shift was observed for the blank solution and with the solution containing different inhibitors. The shifting mechanism toward the negative zone on the addition of the inhibitor shows the cathodic effect, , and the stabilization time of 1 h was adequate to attain the equilibrium state. The negative trend became more pronounced with an increase in N,S codoped Ti 3 C 2 T x MXene at varying concentrations compared to the pure Ti 3 C 2 T x MXene even at 100 ppm.…”

Evaluation of Expired Moxifloxacin Drug as Corrosion Inhibitor for Copper in Synthetic Acid Rain (SAR) Solution

“…This observation suggests that the MOXI does not alter the mechanism underlying the cathodic reaction. However, it does impede corrosion processes by decreasing reaction rates 34 , the minor variation in the cathodic Tafel slope (bc) values.…”