Multifaceted insights of experimental, surface, and computational investigations for a synthesized pyrazolyl derivative inhibitor for carbon steel corrosion in an acidic environment

Two derivatives of 8-quinolinols, namely 2-amino-N-((8-hydroxyquinolin-5-yl)methyl)acetamide (AHQA) and 2,2,2-trifluoro-N-((8-hydroxyquinolin-5-yl)methyl)acetamide (TFQA), were synthesized, characterized, and evaluated as corrosion inhibitors for the dissolution of carbon steel (CS) in 1 M HCl solution. The inhibition effects of AHQA and TFQA on CS corrosion in 1 M HCl solutions were investigated using open circuit potential (OCP) curves, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), UV-visible spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), atomic force microscopy (AFM), as well as density functional theory (DFT) and molecular dynamics (MD) simulations. The results show that AHQA and TFQA are excellent anti-corrosion inhibitors within the temperature range of 303–333 K, and their inhibition performance depends on temperature and concentration; notably, at 10−3 M, the corrosion inhibition efficiencies were 96.3% for AHQA and 95.3% for TFQA. The PDP results indicate that AHQA and TFQA act as mixed-type inhibitors. The chemisorption of these compounds on the CS surface follows the Langmuir adsorption isotherm. The substrate surface composition analysis employed by UV-visible spectroscopy and the surface characterization investigated by SEM-EDX and AFM confirmed that TFQA and AHQA adsorb onto the CS surface to form the 8-quinolinols-Fe protective film, which successfully shields the CS from corrosive ions. Quantum chemical parameters align well with the experimental results, supporting a higher inhibition efficiency of AHQA due to the electron-donating effect of the -CH2-NH2 substituent, compared to TFQA, which contains the electron-withdrawing -CF3 group. Additionally, the MD simulation shows that AHQA and TFQA adsorb onto the Fe(110) surface in a flat orientation.

Di-imine Schiff base inhibitor for carbon steel corrosion in 1 M HCl: Electrochemical, surface and theoretical investigations

Some quinazoline derivatives such as: 3-(4-chlorophenyl)-2-methylquinazolin-4(3H)-one (CMQ) and 2-methyl-3-(4-nitrophenyl) quinazolin-4(3H)-one (MNQ) were investigated as corrosion inhibitors for carbon steel in 2 M HCl solution. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, electrochemical frequency modulation and weight loss methods were used to study the inhibition action at 30°C. The corrosion of steel was controlled by a charge transfer process at the prevailing conditions. The electrochemical results showed that these compounds are efficient inhibitors for carbon steel and efficiency up to 93.8% was obtained at 30°C. The inhibition efficiency increases with inhibitor concentration. The adsorption of these compounds on carbon steel surface follows the Langmuir adsorption isotherm. Polarization curves indicate that investigated quinazoline derivatives are mixed-type inhibitors. The chemical and electrochemical methods gave similar results. Key words: Corrosion inhibitors, hydrogen acid (HCl), carbon steel, quinazoline derivatives.

Three new organic compounds primarily based on 8-hydroxyquinoline have been successfully synthesized and characterized via different spectroscopic methods (FTIR, 1H, and 13C NMR). The synthesized compounds, namely 5-propoxymethyl-8-hydroxyquinoline (PMHQ), 5-methoxymethyl-8-hydroxyquinoline (MMHQ) and 5-hydroxymethyl-8-hydroxyquinoline (HMHQ), were evaluated as corrosion inhibitors for carbon steel in 1 M HCl solution using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss measurements at 298 K. Electrochemical measurements confirmed that the newly synthesized 5-alkoxymethyl-8-hydroxyquinoline derivatives are mixed type corrosion inhibitors and confirmed maximum protection efficiencies of 94, 89 and 81% for PMHQ, MMHQ, and HMHQ, respectively, at the optimum concentration of 10-3 M. The EIS spectra confirmed a slightly depressed semi-circle profile with a single time constant in Bode diagrams for the three organic compounds over the whole concentration and temperature ranges studied. The adsorption of PMHQ, MMHQ, and HMHQ on the carbon steel surface followed the Langmuir adsorption isotherm. In addition, the kinetic and thermodynamic parameters for carbon steel corrosion and inhibitor adsorption, respectively, were determined and discussed. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses supported the formation of a protective film on carbon steel in the presence of PMHQ, MMHQ, and HMHQ. Density functional theory calculations (DFT) showed that the effectiveness of the inhibitive actions of the studied compounds correlates well with their electron donating ability, whilst Monte Carlo simulations revealed that the extent and favourability of adsorption of inhibitor molecules on the carbon steel surface establish their corrosion inhibition performances.

Potential anticorrosive performance of green and sustainable inhibitor based on cellulose derivatives for carbon steel

The inhibitory effect of some nonionic surfactants on the corrosion behavior of two carbon steel type OL 37 and OLC45 in 1M H2SO4 at temperature of 25°C was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FT-IR) and metallurgical microscopy techniques. In the present study, three types of organic inhibitors Span 80, Tween 80 and Tween 60 were investigated. The effect of inhibitor concentration on the corrosion rate, surface coverage and inhibition efficiency is investigated. Results show that these organic inhibitors exert a strong inhibiting effect on carbon steel corrosion and acts as a mix-type inhibitor. The inhibition efficiency of organic inhibitors may be due to either the adsorption of inhibitor molecules building a protective film or the formation of an insoluble complex of the inhibitor adsorption obeys the Langmuir model. Further, characterization using FT-IR demonstrates the adsorption of inhibitors and the formation of corrosion products on the electrode surface. The inhibition process was attributed to the formation of the adsorbed film on the carbon steel surface that protects the material against corrosive agents. The EIS measurements have confirmed this protection and pointed out the formation of adsorption layers on the electrode surface. The metallographic micrographies made before and after the potentiodynamic polarizations pointed out the evolution of the corrosion process. The addition of the organic inhibitors led in all the cases to inhibition of the corrosion rate.The inhibitory effect of some nonionic surfactants on the corrosion behavior of two carbon steel type OL 37 and OLC45 in 1M H2SO4 at temperature of 25°C was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FT-IR) and metallurgical microscopy techniques. In the present study, three types of organic inhibitors Span 80, Tween 80 and Tween 60 were investigated. The effect of inhibitor concentration on the corrosion rate, surface coverage and inhibition efficiency is investigated. Results show that these organic inhibitors exert a strong inhibiting effect on carbon steel corrosion and acts as a mix-type inhibitor. The inhibition efficiency of organic inhibitors may be due to either the adsorption of inhibitor molecules building a protective film or the formation of an insoluble complex of the inhibitor adsorption obeys the Langmuir model. Further, characterization using FT-IR demonstrates the adsorption of inhibitors and the formation of corrosion products on the electrode surface. The inhibition process was attributed to the formation of the adsorbed film on the carbon steel surface that protects the material against corrosive agents. The EIS measurements have confirmed this protection and pointed out the formation of adsorption layers on the electrode surface. The metallographic micrographies made before and after the potentiodynamic polarizations pointed out the evolution of the corrosion process. The addition of the organic inhibitors led in all the cases to inhibition of the corrosion rate.

Insight into the anti–corrosion behavior of Reineckia Carnea leaves extract as an eco–friendly and high–efficiency corrosion inhibitor

The inhibition effect of dicyandiamide (DCDA) on the carbon steel (CS) corrosion in 0.5 M HCl solution was evaluated using chemical and electrochemical methods. The maximum inhibition efficiency (%IE) and the optimal dose were 95.7% and 0.30 mg/L of DCDA inhibitor, respectively. The temperature effect in the %IE is measured using chemicals by gravimetric loss tests. Potentiodynamic polarization (PD‐P) tests clarified that DCDA is a mixed‐type inhibitor, while EIS tests revealed that the charge transfer resistance ( R ct ) increased with inhibitor concentration. The mixed (chemical and physical) adsorption mode appears on the CS surface following a Langmuir isotherm. UV–vis spectra revealed the chemical interaction of DCDA with the CS surface. Atomic force microscopy (AFM) examination revealed the creation of a protective film from DCDA molecules on the metal surface. Correlations between experimental data and theoretical energies derived from DFT analysis were computed using the density functional theory (DFT) method. Additionally, explore the favorite active sites of the DCDA molecule and their interactions with the CS surface.

Herein, we synthesized two novel triazole compounds (KB1 and KB2). Their efficiency in inhibiting corrosion of carbon steel (CS) in 0.5 M H2SO4 was evaluated using open circuit potential (OCP) vs. time, potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), surface characterization methods, and computational studies. Based on EIS, the corrosion protection capacities of KB1 and KB2 increased with increasing concentration, reaching 86.9% and 92.4% at 9 × 10- 5 M at 298K for KB1 and KB2, respectively, which are consistent with the findings obtained via PP. The PP curves imply that KB1 and KB2 act as mixed-type inhibitors. Meanwhile, their adsorption on the surface of CS obeyed the Langmuir isotherm. Using EIS and PP approaches, the effect of temperature on corrosion behavior was examined. As the temperature increased from 298 to 318K, the efficacy of the inhibitors improved, then decreased at 328K. This suggests that KB1 and KB2 may desorb from the CS at 328K. The activation and adsorption parameters were computed and discussed. The effect of immersion time on CS corrosion was documented. The Rct values of the KB2 compound peaked at 2770.0 Ω cm2 after 6h of immersion, later declining to 2685.0 Ω cm2 after 93h, thus evidencing the enhanced stability of the inhibitor's protective layer on the CS surface. Additionally, the steel surface was found to be positively charged in the H2SO4 solution, as indicated by the potential of zero charge (PZC) measurements using EIS. Surface morphology analysis using Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) demonstrated the formation of a protective layer with a high degree of coverage at 9 × 10- 5 M. The test solutions were analyzed via UV-visible spectroscopy to determine whether complex formation between inhibitor molecules and Fe2+ ions is possible. The mechanism of inhibition was better understood via quantum chemical indices (based on DFT). The configurational adsorption performance of KB1 and KB2 on the Fe (110) surface was investigated via Monte Carlo (MC) simulation, which revealed that inhibitors adsorbed on the Fe surface in a flat orientation. These results are thought to have some bearing on the sensible development of potent inhibitors for acidic corrosion.

Three novel morpholinium-cationic surfactants (coded: DCSM-8, DCSM-10, and DCSM-12) with chemical structure confirmed via FT-IR, HNMR, and mass analysis were applied for carbon steel (CS) corrosion control in acidic 4 M HCl solution. The investigated compounds decreased water surface tension (72 mN.m-1) to 19.85 mN.m-1 after the addition of DCSM-12. The surfactants mitigation performance was assessed via weight loss (WL), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The synthesized surfactants protected CS efficiently with higher inhibition efficiencies up to 97.029% at 1 × 10–3 M for DCSM-12 using PDP which also indicated that, the prepared surfactants inhibited both CS anodic and cathodic sites with cathodic dominant. EIS data showed higher CS resistance from 35.24 Ω.cm2 to 1245.54 Ω.cm2 after addition of 1 × 10–3 M for DCSM-12 with mitigation potency 97.17% which can be attributed to their adsorption process over CS surface forming a protective film layer that followed Langmuir adsorption isotherm reflecting the chemical adsorption affinity of the prepared mitigators with higher adsorption energy (ΔG*ads) values (> -40 kJ.mol-1). Also, the protection effect of the prepared inhibitor (DCSM-12) was confirmed using SEM (scanning electron microscopy) and EDX (energy-dispersive X-ray) showing improvement in CS surface morphology. The reactivity of the prepared surfactants and their mitigation role in CS deterioration were confirmed theoretically using DFT (density functional theory) and MCs (Monte Carlo simulations).

This paper studies the use of zinc oxide nanoparticles (ZnO-NPs) synthesized using an extract of Convolvulus arvensis leaf and expired ZnCl2, as efficient inhibitors of carbon steel corrosion in a 1 M HCl solution. The synthesized ZnO-NPs were characterized by Fourier-transform infrared (FTIR) and UV-Vis spectroscopy analysis. The corrosion inhibition of carbon steel in 1 M HCl was also investigated through potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and the determination of weight loss. The results show that the efficiency of the prevention increased when the concentration of ZnO-NPs was increased to 91%, and that the inhibition efficiency was still high (more than 89%) despite decreasing at high temperatures, acting as a mixed-type inhibitor. A sample of carbon steel with a protective layer of inhibitor on top was observed during immersion in 1 M HCl for 20 h; an increase in the charge transfer resistance (Rct) and stability of the inhibitor could be observed after 6 h. Adsorption isotherm models demonstrated that the inhibitor adsorption mechanism on the carbon steel surface followed Langmuir rather than Freundlich and Temkin behaviors. The thermodynamic parameters showed that the adsorption process is one of mixed, spontaneous, and exothermic adsorption. The results illustrate that the ZnO-NPs were a strong inhibitor of carbon steel corrosion in acid medium. The results of scanning electron microscopy (SEM) images showed that the ZnO-NPs formed a good protective film on the carbon steel surface.

Electrochemical, DFT and MD simulation of newly synthesized triazolotriazepine derivatives as corrosion inhibitors for carbon steel in 1 M HCl

In this work, cationic Gemini surfactantswith different alkylchain lengths (n = 8, 10, and 12) and a bipyridylspacer were synthesized and tested as corrosion inhibitors for carbonsteel in 1 M HCl solution. The corrosion inhibition efficiency wasdetermined by weight loss measurement, potentiodynamic polarization,and electrochemical impedance spectroscopy. Results showed that suchthree inhibitors could effectively inhibit the corrosion of carbonsteel in 1 M HCl solution, especially at their low concentrations,while the carbon chain length of Geminis used played a negligiblerole in the inhibition efficiency. Scanning electron microscopy/energydispersive X-ray analysis observations demonstrated the formationof a protective inhibitor layer on the carbon steel surface. Additionally,the adsorption of the inhibitor molecules on the carbon steel surfacewas found to obey the Langmuir isotherm.

The corrosion inhibition of 2-(benzylthio)-1,4,5-triphenyl-1H-imidazole (BTI) for carbon steel in a 1 M HCl solution was studied by means of weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) methods. Quantum chemical calculations based on the DFT method were performed on BTI. Molecular dynamics simulations were carried out to establish the mechanism of corrosion inhibition for carbon steel with BTI in HCl. Kinetic and thermodynamic parameters of activation using a statistical model were calculated. Polarization curves revealed that BTI is a mixed-type inhibitor. The results showed that BTI is a good inhibitor for the corrosion of carbon steel in 1.0 M HCl solution and that its inhibition efficiency is higher than 88% at 1 × 10–3 M BTI. Adsorption of the inhibitor on the carbon steel surface follows the Langmuir adsorption isotherm, and the value of the free energy of adsorption, ΔGads, indicates that the adsorption of BTI is a s...

Corrosion of carbon steel is a major problem that destroys assists of industries and world steel installations; the importance of this work is to introduce new heterocyclic compounds as effective and low-cost corrosion inhibitors. Three compounds of carbohydrazide derivatives, namely: 5-amino-N′-((2-methoxynaphthalen-1-yl)methylene)isoxazole-4-carbohydrazide (H4), 2,4-diamino-N′-((2-methoxy-naphthalene-1-yl)methylene) pyrimidine-5-carbohydrazide (H5) and N′-((2-methoxynaphthalen-1-yl)methylene)-7,7-dimethyl-2,5-dioxo-4a,5,6,7,8,8a-hexahydro-2H-chromene-3-carbohydrazide (H6) were used to examine the efficacy of corrosion of carbon steel in 1 M hydrochloric acid solution. This corrosion efficacy was detected by utilizing various methods including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), weight loss measurements (WL), surface morphology analyses by atomic force microscopy (AFM), quantum chemical computations based on density functional theory (DFT) and molecular dynamics (MD) simulation. The results indicated that these compounds act as mixed type inhibitors i.e. reduce the corrosion rate of carbon steel due to the formation of a stable protective film on the metal surface and reduce the cathodic hydrogen evolution reaction. As confirmed from impedance, carbohydrazide derivatives molecules are adsorbed physically on metal surface with higher corrosion efficacy reached to (81.5–95.2%) at 20 × 10−6 M concentration at room temperature. Temkin isotherm model is the most acceptable one to describe the carbohydrazide derivative molecules adsorption on the surface of carbon steel. Protection mechanism was supported by quantum chemical analyses and Monte Carlo modeling techniques. The theoretical calculations support the experimental results obtained. This proves the use of carbohydrazide derivatives as a very effective inhibitors against the corrosion of carbon steel in acidic media.