Author(s)

N’guessan Yao Silvère Diki^1*, Nagnonta Hippolyte Coulibaly², Ollo Kambiré², Albert Trokourey¹

¹Laboratoire de Constitution et Réaction de la Matière, UFR SSMT, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire.
²UFR Sciences et Technologies, Université de Man, Man, Côte d’Ivoire.

Cefixime, a third-generation semi-synthetic cephalosporin antibiotic was used as a copper corrosion inhibitor in 1M HNO₃ solution. The study was conducted through the weight loss technique at 298 - 318 K and theoretical studies based on quantum chemistry. The studied drug inhibited the corrosion of copper in 1M HNO₃ over the cefixime concentration range (0.02 - 2 mM). The inhibition efficiency increased with an increase in the inhibitor concentration to reach 91.07% at 2 mM, but decreased with an increase in temperature. The thermodynamic functions related to the adsorption of cefixime on the copper surface and that of the metal dissolution were computed and analyzed. The results point out spontaneous adsorption, mainly through a physisorption mechanism following Langmuir adsorption isotherm model and an endothermic dissolution process. Quantum chemical calculations were also performed at B3LYP level with 6-31G (d, p) basis set and lead to molecular descriptors such as E_HOMO (energy of the highest occupied molecular orbital), E_LUMO (energy of the lowest unoccupied molecular orbital), ΔE (energy gap) and μ (dipole moment). The global reactivity descriptors such as χ (electronegativity), χ (global hardness), S (global softness), and ω (electrophilicity index) were derived using Koopman’s theorem and analyzed. The local reactivity parameters, including Fukui functions and dual descriptors were determined and discussed. Experimental and theoretical results were found to be in good agreement.

Cefixime, Corrosion, Langmuir, Quantum Chemistry, Weight Loss

Diki, N. , Coulibaly, N. , Kambiré, O. and Trokourey, A. (2021) Experimental and Theoretical Investigations on Copper Corrosion Inhibition by Cefixime Drug in 1M HNO₃ Solution. Journal of Materials Science and Chemical Engineering, 9, 11-28. doi: 10.4236/msce.2021.95002.