DFT/electronic scale, MD simulation and evaluation of 6-methyl-2-(p-tolyl)-1,4-dihydroquinoxaline as a potential corrosion inhibition
- Publication Type
- Original research
- Authors
Abstract
Mild steel (MS) is a material frequently used in industry, but it usually suffers from extensive corrosion in the acidic environment. To reduce this processor, we used the quinoxaline molecule substituted (6-methyl-2-(p-tolyl)-1,4-dihydroquinoxaline ((CH3)2Q) with electron donor group. Corrosion inhibition potency of CH3)2Q on MS in 1 M HCl was first evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The effect of (CH3)2Q over the MS surface was analyzed by scanning electron microscope (SEM). The parameters of adsorption of the (CH3)2Q on the MS surface are determined. To better understanding of corrosion inhibition mechanisms, theoretical investigations were carried out namely the DFT, molecular dynamics simulations (MDS), radial distribution function (RDF) and mean square displacement (MSD). The outcomes of our investigation spurred us to deduce that (CH3)2Q behave as effective inhibitor for MS corrosion in 1 M HCl at all tested concentrations, the efficiency of the inhibition reaches a maximum value which equals 93.50% at 10-3 M. The type of inhibition mechanism for (CH3)2Q was mixed-type. A CPEn, Q determined by fit and graphical methods plotted by synthetic data, was utilized. The EIS findings revealed that the addition of (CH3)2Q to the corrosive medium leads to a decrease of the charge capacitance resulting in a systematic improve of the interface charge/discharge function and forms an adsorbed layer over the metal surface. The Langmuir isotherm proved the highest compliance with experimental data, representing the generation of protective mono-layer of inhibitors on the MS substrate. The effect of (CH3)2Q over the MS surface was analyzed by scanning electron microscope (SEM). The parameters of adsorption of the (CH3)2Q on the MS surface are determined. The results show that (CH3)2Q could offer an inhibition efficiency of 93.50 and 77.35% at 303 and 333 K, respectively. The local reactivity and distribution of the electronic density of HOMO/ LUMO shows that the molecules analyzed contain highly reactive centers distributed throughout the molecular structure. New insights were contributed by diffusion model and RDF method.
- Title
- Ismail Warad
- Publisher
- Ismail Warad
- Publisher Country
- Palestine
- Publication Type
- Prtinted only
- Volume
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- Year
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- Pages
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