New 8-Hydroxyquinoline-Bearing Quinoxaline Derivatives as Effective Corrosion Inhibitors for Mild Steel in HCl: Electrochemical and Computational Investigations

Abstract

There has been substantial research undertaken on the role of green synthesized corrosion inhibitors as a substantial approach to inhibit the corrosion of metals and their alloys in acidic environments. Herein, electrochemical studies, surface characterization, and theoretical modeling were adopted to investigate the corrosion inhibition proprieties of novel synthesized quinoxaline derivatives bearing 8-Hydroxyquinoline, namely 1-((8-hydroxyquinolin-5-yl) methyl)-3,6-dimethylquinoxalin-2(1H)-one (Q1) and 1-((8-hydroxyquinolin-5-yl)methyl) quinoxalin-2(1H)-one (Q2) on mild steel corrosion in 1 mol/L HCl solution. The principal finding of this research was that both inhibitors acted as good corrosion inhibitors with Q1 having the highest performance (96% at 5 × 10−3 mol/L). Electrochemical results obtained via potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques demonstrated that quinoxaline compounds belonged to mixed-type inhibitors; their presence significantly increased the polarization resistance, preventing simultaneously anodic and cathodic reactions. Further, experimental results provided preliminary insights about the interactions mode between studied molecules and the mild steel surface, which followed the Langmuir adsorption model, and physical and chemical interactions assisted their inhibition mechanism. Besides, SEM analyses confirmed the existence of protective film on the metal surface after the addition of 5 × 10−3 mol/L of quinoxalines. In addition, the temperature and immersion time effects on inhibition performances of quinoxalines were investigated to evaluate their performances in different operating conditions. Besides, Density Functional Theory (DFT) and molecular dynamics (MD) simulations were carried out to explore the most reactive sites of quinoxaline inhibitors and their interaction mechanism. Theoretical results revealed that the inhibitor molecule with additional electron-donating functional group strongly interacted with the steel surface.

Optical and Photovoltaic Properties of New Synthesized Quinoxaline-2,3 Dione Derivatives for Efficient Dye Sensitized Solar Cell Application

“…The quinoxalinedione derivatives have attracted attention in several molecular applications [1][2][3][4]. Synthesis, energetic and structural properties of some quinoxalinedione derivatives were made by our group [5][6][7][8][9][10]. Spectroscopic data are in agreement with literature [5,8,10].…”

“…Synthesis, energetic and structural properties of some quinoxalinedione derivatives were made by our group [5][6][7][8][9][10]. Spectroscopic data are in agreement with literature [5,8,10]. Organic photovoltaic solar cells (OPVSC) pose an important potential for progress in the work for electricity production from low-cost compounds.…”

Organic Compounds as Corrosion Inhibitors for Carbon Steel in HCl Solution: A Comprehensive Review

“…Figure 7 shows the RDF analysis results stemming from the consequence of the MD simulation data of two quinoxaline derivative inhibitor molecules (Q1 and Q2) cited in the literature [ 134 ]. These results are shown in the form of a plot of the distance r versus the probability g(r).…”

An Overview of Molecular Dynamic Simulation for Corrosion Inhibition of Ferrous Metals

“…Contrarily, Zhu et al [59] demonstrated the use of Fe(100) surface as the adsorption site for 2-aminobenzimidazole derivative inhibitor. The order of surface energy of the iron surface is Fe(110) < Fe(100) < Fe (111), which makes Fe (110) to be the most stable, followed by Fe(100) and Fe (111) facets [60]. Regardless of the type of ferrous metal (carbon steel, alloy steel or stainless steel) studied experimentally, pure iron atoms instead of a mixture of iron with alloying elements are usually used for theoretical studies [11,38,[61][62][63].…”