Computational Stimulation and Experimental Study on Corrosion Inhibition Qualities of Emilia sonchifoliaLeaf Extract for Copper (CU131729) in Hydrochloric Acid

摘要

Copper corrosion inhibition by Emilia sonchifolia (ES) leaf extract has been studied in 2 M hydrochloric acid solution using electrochemical measurement, energy dispersive X-ray emission spectroscopy and surface examination techniques. Computational simulations were adopted to describe probable reactiveness of individual ES leaf constituents and mechanism of interaction with copper crystal. Results obtained from potentiodynamic polarization revealed a shift in corrosion potentials of copper (CU131729) to more positive potentials in the presence of ES leaf extract with increased effect as inhibitor concentration increased and also a decrease in both current densities suggesting a mixed type inhibitor characteristics with pronounced anodic protection. Surface elemental characterization revealed presence of the inhibitor species in the corrosion products formed on corroded CU131729 surface confirming the formation of complex chelating ligands through interactions with the metal surface. Quantum chemical calculations and molecular dynamics simulations were employed to theoretically analyse the interactions of individual ES leaf constituent with copper surface at the molecular level and obtained results revealed strong and spontaneous adsorption with high binding energies which affirms observed quality inhibition action. Quantum chemical descriptors such as energy of HOMO and LUMO, energy gap, number of transferred electrons, global hardness and softness, electrophilicity, and interaction energy were computed and discussed.