Density functional theory and molecular dynamic simulation studies on the corrosion inhibition of some thiosemicarbazide derivatives on aluminum metal

Abstract

Aluminum (Al), one of the most comercially used metals is also susceptible to corrosion like iron and zinc when subjected to corrosive environments, either in the industries or during applications in general. One major method of controlling corrosion of Al is through the use of inhibitors which are usually compounds containing heteroatoms, conjugated systems or which are relatively large in size. One of such inhibitors, thiosemicarbazide derivatives were reported in literature as an Al inhibitor in 2M HCl solution through experimental studies. In this study, computational methods were used to further provide an indepth explanation into the mode and mechanism of the thiosemicarbazides inhibition on Al surface. Parameters including quantum chemical through DFT and molecular dynamic simulations of studied molecules on Al surfaces were conducted. Results obtained through calculation of adsorption or binding energies of these thiosemicarbazides were in good agreement with the experimentally reported results elsewhere. With respect to the calculated adsorption or binding energies, thier relatively low values infered that the compounds are weakly adsorbed onto the surface of Al through Van der Waals forces and therefore obey the mechanism of physical adsorption. It was also established that the reference molecule thiosemicarbazide (TSC) was least adsorbed when compared to the other five molecules of its derivatives. The order of the inhibition efficiency as determined is as follows: PBT>DTC>DPT>PCT>PTC>TSC