Novel cost-effective and high-performance green inhibitor based on aqueous Peganum harmala seed extract for mild steel corrosion in HCl solution: Detailed experimental and electronic/atomic level computational explorations

Synthesis of Gemini-type imidazoline quaternary ammonium salt using by-product fatty acid as corrosion inhibitor for Q235 steel

Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA).

Experimental and theoretical insights into Artemisia Stems aqueous extract as a sustainable and eco-friendly corrosion inhibitor for mild steel in 1 M HCl environment

The present research demonstrates an innovative investigation of environmentally friendly mild steel (M-steel) corrosion inhibition using the artemisia stems aqueous extract (ASAEx) as an inhibitor in hydrochloric acid 1 M. The standard extraction technique of hydrodistillation was used for producing the aqueous solutions of ASAEx. To assess the ratios of the chemical components, phytochemical screening was used to identify the stems of this plant. We used a variety of methods and techniques in our research on corrosion inhibition, including weight loss measures, surface analysis methods like XPS and SEM/EDS, electrochemical testing like PDP and EIS, as well as computational lead compound evaluation. Maximum inhibitory efficacy was achieved with 400 mg/L ASAEx in 1 M HCl at 303 K, i.e. 90%. The PDP investigation verified the mixed-kind inhibitor status of the ASAEx extract. To describe the surface of M-steel, fitting and synthetic data were used to identify a constant phase element (CPE). SEM surface analysis was also used to detect the ASAEx effect on the surface of M-steel. X-ray photoelectron spectroscopy (XPS) analysis shows the presence of trace molecules of ASAEx on M-steel surface characterizing the bands in Maj-ASAEx (major compound of ASAEx). Density functional theory (DFT) and molecular dynamics simulations (MDs) were used in computational chemistry to clarify the adsorption mechanism and inhibitory impact.

Pumpkin Leaf Extract Crop Waste as a New Degradable and Environmentally Friendly Corrosion Inhibitor

The pumpkin leaf was extracted by the decoction method, and it was used as an eco-friendly, nontoxic inhibitor of copper in 0.5 M H2SO4 corrosion media. To evaluate the composition and protective capacity of the pumpkin leaf extract, Fourier infrared spectroscopy, electrochemical testing, XPS, AFM, and SEM were employed. The results showed that the pumpkin leaf extract (PLE) is an effective cathode corrosion inhibitor, exhibiting exceptional protection for copper within a specific temperature range. The corrosion inhibition efficiency of the PLE against copper reached 89.98% when the concentration of the PLE reached 800 mg/L. Furthermore, when the temperature and soaking time increased, the corrosion protection efficiency of 800 mg/L PLE on copper consistently remained above 85%. Analysis of the morphology also indicated that the PLE possesses equally effective protection for copper at different temperatures. Furthermore, XPS analysis reveals that the PLE molecules are indeed adsorbed to form an adsorption film, which is consistent with Langmuir monolayer adsorption. Molecular dynamics simulations and quantum chemical calculations were conducted on the main components of the PLE.

Assessment of Hydrazone Derivatives for Enhanced Steel Corrosion Resistance in 15 wt.% HCl Environments: A Dual Experimental and Theoretical Perspective

This study evaluates the corrosion inhibition capabilities of two novel hydrazone derivatives, (E)-2-(5-methoxy-2-methyl-1H-indol-3-yl)-N'-(4-methylbenzylidene)acetohydrazide (MeHDZ) and (E)-N'-benzylidene-2-(5-methoxy-2-methyl-1H-indol-3-yl)acetohydrazide (HHDZ), on carbon steel in a 15 wt.% HCl solution. A comprehensive suite of analytical techniques, including gravimetric analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM), demonstrates their significant inhibition efficiency. At an optimal concentration of 5 × 10-3 mol/L, MeHDZ and HHDZ achieve remarkable inhibition efficiencies of 98% and 94%, respectively. EIS measurements reveal a dramatic reduction in effective double-layer capacitance (from 236.2 to 52.8 and 75.3 µF/cm2), strongly suggesting inhibitor adsorption on the steel surface. This effect is further corroborated by an increase in polarization resistance and a significant decrease in corrosion current density at optimal concentrations. Moreover, these inhibitors demonstrate sustained corrosion mitigation over extended exposure durations and maintain effectiveness even under elevated temperatures, highlighting their potential for diverse operational conditions. The adsorption process of these inhibitors aligns well with the Langmuir adsorption isotherm, implying physicochemical interactions at the carbon steel surface. Density functional tight-binding (DFTB) calculations and molecular dynamics simulations provide insights into the inhibitor-surface interaction mechanism, further elucidating the potential of these hydrazone derivatives as highly effective corrosion inhibitors in acidic environments.

Electrochemical and computational insights into the utilization of 2, 2- dithio bisbenzothiazole as a sustainable corrosion inhibitor for mild steel in low pH medium

Industries today place a high premium on environmentally friendly supplies that may effectively inhibit metal dissolution at a reasonable cost. Hence, in this paper, we assessed the corrosion inhibition effectiveness of the Thiazole derivative namely, 2, 2-Dithio Bisbenzothiazole (DBBT) against mild steel (MS) corrosion in 1 M HCl. Several experimental approaches, including gravimetric analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and surface exploration using scanning electron/atomic force microscopy (SEM/AFM) and contact angle (CA), were utilized to conduct the measurements. In 1 M HCl corrosive medium at 298 K in the subsistence of 800 ppm of DBBT, this experiment indicated DBBT as an environment-friendly and sustainable corrosion inhibitor (CI) for MS, demonstrating an inhibition efficiency (IE %) of 97.71%. To deliver a deeper knowledge of the mechanism behind inhibitive behavior, the calculated thermodynamic and activation characteristics were applied. The calculated Gibbs free energy values indicated that the CI interacted physically and chemically with the MS surface, validating physio-chemical adsorption. The findings of the EIS research revealed that an upsurge in the doses of the CI is escorted by an upsurge in polarization resistance (Rp) from (88.05 → 504.04) Ωcm2, and a diminution in double layer capacitance (Cdl) from (97.46 → 46.33) μFcm-2 at (50 → 800) ppm respectively, affirming the inhibitive potential of DBBT. Additionally, the greatest displacement in Ecorr value being 76.13 mV < 85 mV, indicating that DBBT act as a mixed-form CI. To study the further impacts of DBBT on the inhibition capabilities of the compound under investigation, density functional theory (DFT) and molecular dynamics (MD) simulation were employed. Chemical and electrochemical approaches are in agreement with the computational analysis indicating DBBT is the most efficient CI.

An eco-friendly corrosion inhibitor Cuscuta reflexa extract and PEG400 for mild steel inhibition in acidic medium: computational and experimental investigations

Herein, the mechanism of corrosion prevention of mild steel (MS) by extract of Cuscuta reflexa/Amarbel (AME) as green inhibitor is explained by gravitational, electrochemical measurements. The viability of neat extract and after adding an intensifier was investigated as corrosion inhibitor for MS in hydrochloric acid. The presence of electron-rich moieties in AME was characterized through Fourier-transform infrared spectroscopy (FTIR). Furthermore, polarization measurements showed that AME acted as a mixed type inhibitor against corrosion. The formulation of 100 ppm AME with 50 ppm polyethylene glycol 400 (PEG400) as an intensifier showed inhibition efficiency of 97.51% for MS in 0.5 M HCl. The protection of MS in (AME + PEG) formulation was also assessed through the Langmuir, Freundlich, and Flory-Huggins adsorption isotherm model. The surface studies of the MS were examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM) that indicated a smoothened surface of the metal in the presence of the studied compounds. XPS study was executed to analyze the interaction of the inhibitor with the metal surface. In addition, computational quantum study provides the molecular structural relationship with corrosion inhibitive competence of the extract.

Developing novel imidazoline-modified glucose derivatives as eco-friendly corrosion inhibitors for Q235 steel

Many natural compounds and imidazoline derivatives have been previously evaluated as eco-friendly corrosion inhibitors for application in the food, pharmaceutical and chemical industries. Herein, a novel alkyl glycoside cationic imaginary ammonium salt (FATG) was designed via the grafting of imidazoline molecules into the skeleton of a glucose derivative, and its effects on the electrochemical corrosion behavior of Q235 steel in 1 M HCl were systemically investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves (PDP), and gravimetric measurements. The results indicated that its maximum inhibition efficiency (IE) was 96.81% at a concentration as low as 500 ppm. The adsorption of FATG on the Q235 steel surface followed the Langmuir adsorption isotherm. The scanning electron microscopy (SEM) and diffraction X-ray (XRD) results suggested the formation of inhibitor film on the metal surface, which significantly impeded the corrosion of Q235 steel. Additionally, FATG showed a high biodegradability efficiency (98.4%), which had great potential as a green corrosion inhibitor based on concepts of greenness and biocompatibility.

Inhibitory behavior and adsorption of asparagine dipeptide amino acid on the Fe(111) surface

CONTEXT

The inhibitory effect of asparagine (Asn) and its derivatives on iron (Fe) corrosion was studied by performing density functional theory (DFT) calculations. In this paper, the global and local reactivity descriptors of Asn in the protonated and neutral forms were evaluated. Also, the changes in reactivity were investigated when dipeptides were combined with Asn. Due to the increase in the reaction centers within their molecular structure, there was an enhancement in the inhibitory effect of these dipeptides. Moreover, the adsorption energies (E_ads) and the adsorption configurations of Asn and small peptides (SPs) with most stability were determined on the surface of Fe(111). It was found that dipeptides had a chemical adsorption on these substrates. In the protonated forms, there was an enhancement in the absolute values of E_ads between the inhibitors and the Fe(111) surfaces. Peptides were more likely to be adsorbed on the Fe surfaces, showing the great inhibitory effect of these moieties. The results of the current research demonstrate the possibility of utilizing SPs as efficient "green" corrosion inhibitors.

METHODS

DFT computations were undertaken by employing the BIOVIA Material Studio with B3LYP-D3 functional and 6-31 + G* basis set. The theoretical evaluation of the inhibitory effect of asparagine (Asn) dipeptides, and the potential analysis of small peptides to protect against the corrosion of Fe, was done.

Investigation of synthesized ethyl-(2-(5-arylidine-2,4-dioxothiazolidin-3-yl) acetyl) butanoate as an effective corrosion inhibitor for mild steel in 1 M HCl: A gravimetric, electrochemical, and spectroscopic study

The corrosion inhibition effects of five concentrations (5E-5 M to 9E-5 M) of ethyl-(2-(5-arylidine-2,4-dioxothiazolidin-3-yl) acetyl) butanoate, a novel thiazolidinedione derivative code named B1, were investigated on mild steel in 1 M HCl using gravimetric analysis, electrochemical analysis and Fourier transform infrared spectroscopy. After synthesis and purification, B1 was characterized using nuclear magnetic resonance spectroscopy. All gravimetric analysis experiments were carried out at four different temperatures: 303.15 K, 313.15 K, 323.15 K and 333.15 K, achieving a maximum percentage inhibition efficiency of 92% at 303.15 K. The maximum percentage inhibition efficiency obtained from electrochemical analysis, conducted at 303.15 K, was 83%. Thermodynamic parameters such as ΔG°_ads showed that B1 adsorbs onto the MS surface via a mixed type of action at lower temperatures, transitioning to exclusively chemisorption at higher temperatures.

Inhibition performance of halogen-substituted benzaldehyde thiosemicarbazones as corrosion inhibitors for mild steel in hydrochloric acid solution

Halogen-substituted benzaldehyde thiosemicarbazone derivatives were synthesized and their inhibition performance for mild steel in hydrochloric acid solution were investigated systematically using weight loss measurements, electrochemical techniques, scanning electron microscopy and quantum chemical calculations. Results of weight loss measurements indicated that all these compounds exhibited excellent inhibition performance and the inhibition efficiency increased with increasing inhibitor concentrations. Polarization results revealed that the synthesized benzaldehyde thiosemicarbazone derivatives were mixed-type inhibitors. Adsorption of these compounds onto a mild steel surface was mainly chemisorption and complied with the Langmuir adsorption isotherms. Both theoretical calculations and experimental measurements suggested that the inhibition efficiency of these compounds followed the order of Br-BT > Cl-BT > F-BT > H-BT.

Use of Trochodendron Aralioides Extract as Green Corrosion Inhibitor for Mild Steel in 1M HCl Solutions

Recently, there is an interesting discussion that has transpired around the world about the usage of plant extracts as corrosion inhibitors. We report that to control corrosion in mild steel (MS) specimens in a 1M HCl medium, Trochodendron aralioides (T. aralioides) extract was used as an economical green corrosion inhibitor. The various tests, namely, potentiodynamic polarization, weight loss measurements and electrochemical impedance spectroscopy (EIS) were performed to analyze the inhibition efficiency (IE) of the extract. The highest IE value of 96.42% was seen at 250 ppm, with the IE% increasing as the extract concentration increased. Potentiodynamic polarization suggests that T. aralioides plant extract acts as a mixed-type inhibitor. UV–visible (UV–Vis) and FT-IR spectroscopy were performed with the inhibitor to study the adsorption mechanism and surface analysis of the specimen, respectively. The results revealed that plant extracts form a protective film on the surface of the specimens, increasing inhibition and thereby reducing corrosion. Surface morphological studies such as AFM, EDX and SEM tests were performed in the presence and absence of the inhibitor with the results being analyzed by observing the surface of the metal.

A Brief Review on Fruit and Vegetable Extracts as Corrosion Inhibitors in Acidic Environments

The corrosion of metals, i.e., the initiation and acceleration of the surface deterioration of metals through an electrochemical reaction with the surrounding intrusive environment, is a global concern because of the economic and environmental impacts. Corrosion inhibitors are considered the most practical choice among the available corrosion protection techniques due to their effectiveness in terms of functionality and cost. The use of traditional and toxic corrosion inhibitors has led to environmental issues, arousing the need for green counterparts that are environmentally friendly, easily accessible, biodegradable, and cost-effective. In this review, the utilization of green corrosion inhibitors purely acquired from renewable sources is explored, with an in-depth focus on the recent advancements in the use of fruit and vegetable extracts as green corrosion inhibitors. In particular, fruits and vegetables are natural sources of various phytochemicals that exhibit key potential in corrosion inhibition. To shed light on the true potential of such extracts in the protection of steel in acidic environments, the experimental techniques involved in corrosion inhibition and the mechanism of corrosion inhibition are discussed in detail. The study highlights the potential of fruit and vegetable extracts as non-toxic, economical, and effective corrosion inhibitors in the pursuit of green chemistry. In addition to discussing and outlining the current status and opportunities for employing fruit and vegetable extracts as corrosion inhibitors, the current review outlines the challenges involved in the utilization of such extracts in corrosion inhibition.

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

Most studies on the corrosion inhibition performance of organic molecules and (nano)materials were conducted within “carbon steel/1.0 M HCl” solution system using similar experimental and theoretical methods. As such, the numerous research findings in this system are sufficient to conduct comparative studies to select the best-suited inhibitor type that generally refers to a type of inhibitor with low concentration/high inhibition efficiency, nontoxic properties, and a simple and cost-economic synthesis process. Before data collection, to help readers have a clear understanding of some crucial elements for the evaluation of corrosion inhibition performance, we introduced the mainstay of corrosion inhibitors studies involved, including the corrosion and inhibition mechanism of carbon steel/HCl solution systems, evaluation methods of corrosion inhibition efficiency, adsorption isotherm models, adsorption thermodynamic parameters QC calculations, MD/MC simulations, and the main characterization techniques used. In the classification and statistical analysis section, organic compounds or (nano)materials as corrosion inhibitors were classified into six types according to their molecular structural characteristics, molecular size, and compound source, including drug molecules, ionic liquids, surfactants, plant extracts, polymers, and polymeric nanoparticles. We outlined the important conclusions obtained from recent literature and listed the evaluation methods, characterization techniques, and contrastable experimental data of these types of inhibitors when used for carbon steel corrosion in 1.0 M HCl solution. Finally, statistical analysis was only performed based on these data from carbon steel/1.0 M HCl solution system, from which some conclusions can contribute to reducing the workload of the acquisition of useful information and provide some reference directions for the development of new corrosion inhibitors.

Stachys byzantina extract: A green biocompatible molecules source for graphene skeletons generation on the carbon steel for superior corrosion mitigation

The presence of bio-active compounds in Stachys byzantina (SB) extract has made it a powerful source of green inhibitors in controlling steel corrosion. In this study, it has been attempted to create a highly durable corrosion protective film on the surface of the metal with SB and divalent zinc (II) cations and investigated them by Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic polarization (PP) tests, and surface analysis methods. EIS results show that after 24 h of placing the steel samples in 3.5% NaCl solution containing 700 SB - 300 ZN, the synergistic corrosion inhibition behavior was about 92%. Besides, the results of the PP demonstrated a significant reduction of the icorr. Furthermore, surface analyses such as Field Emission Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (FE-SEM/EDS) and Atomic Force Microscopy (AFM) images illustrated the low metal surface degradation, which indicates that the mix of SB and Zn caused a protective layer creation on the surface, especially for SB 700 - Zn 300. Also, new compounds of graphitic materials' structure were made using SB extract which is a natural-based chemical, and investigated by Fourier-Transform Infrared Spectroscopy (FTIR) test, Grazing Incidence X-ray Diffraction (GIXRD) technique, Ultraviolet-visible spectroscopy (UV-Vis) analysis, and Raman spectroscopy.

Molecular modelling of compounds used for corrosion inhibition studies: a review

Molecular modelling of organic compounds using computational software has emerged as a powerful approach for theoretical determination of the corrosion inhibition potential of organic compounds. Some of the common techniques involved in the theoretical studies of corrosion inhibition potential and mechanisms include density functional theory (DFT), molecular dynamics (MD) and Monte Carlo (MC) simulations, and artificial neural network (ANN) and quantitative structure-activity relationship (QSAR) modeling. Using computational modelling, the chemical reactivity and corrosion inhibition activities of organic compounds can be explained. The modelling can be regarded as a time-saving and eco-friendly approach for screening organic compounds for corrosion inhibition potential before their wet laboratory synthesis would be carried out. Another advantage of computational modelling is that molecular sites responsible for interactions with metallic surfaces (active sites or adsorption sites) and the orientation of organic compounds can be easily predicted. Using different theoretical descriptors/parameters, the inhibition effectiveness and nature of the metal-inhibitor interactions can also be predicted. The present review article is a collection of major advancements in the field of computational modelling for the design and testing of the corrosion inhibition effectiveness of organic corrosion inhibitors.