Steel In Acid Research Articles

Soybean and Glycine as Potential Corrosion Inhibitors for Steel in Hydrochloric Acid: Electrochemical and Morphological Studies

The potential of soybean and glycine as organic corrosion inhibitors for steel in acid solution was examined through weight loss tests and potentiodynamic polarization. Both soybean and glycine were characterized via FTIR and UV-visible. The result shows that the soybean and glycine contain isoflavone and nitrogen bonds respectively as a beneficial element in inhibiting the corrosion of steel. Corrosion tests were performed with and without the presence of soybean and glycine for 3 days of immersion in the acidic medium. Corrosion inhibition efficiency measured via electrochemical test found that both soybean and glycine give an excellent corrosion inhibition efficiency at 1.5 g/L in 0.5 M HCl up to 96% and 94% respectively. Tafel analysis reveals both inhibitors perform mixed types inhibitors which predominantly anodic inhibition. Pseudo-passivation was observed in the Tafel curve indicating the capabilities of both inhibitors to passivate the corrosion at anodic potential. Observation of the steel samples through an optical microscope shows that the corrosion of the steel surface was inhibited in the addition of soybean and glycine in HCl. The roughness of the steel surface affected by the combination of uniform and pitting corrosion was also reduced. In overall, soybean and glycine exhibit excellent anticorrosive properties due to the presence of significant chemical structures and active functional groups. Analysis of the inhibition mechanism through isotherm showed that soybean and glycine followed Langmuir isotherm, indicating the adsorption type for both inhibitors is chemisorption. The results obtained from this study could be a good reference in diversifying the study of amino acids as metal corrosion inhibitors to benefit metal-based industries.

(Digital Presentation) Coffee Extract Assisted Synthesis of Cu2+-Doped NiFe2O4 and Influence on Corrosion for Steel in Acidic Environment

Due to the great importance of looking for new alternatives for the use of agroindustrial waste, it is intended to synthesizeCu2+-doped NiFe2O4 nanoparticles in an environmentally friendly way from extract of the agroindustrial waste coffee pulp, characterizing its structural and anticorrosive properties. A preliminary study of the effect of the concentration of Ni, Cu and Fe on the corrosion of steel in 1M sulfuric acid was developed, using various advanced electrochemical tools such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD). The effect of Cu2+-doped NiFe2O4 on corrosion for steel in acidic environment is promising and of great importance for the industry.

Surface analysis and interface properties of a newly synthesized quinoline-derivative corrosion inhibitor for mild steel in acid pickling bath: Mechanistic exploration through electrochemical, XPS, AFM, contact angle, SEM/EDS, and computational studies

The two novel heterocyclic quinoline derivatives, 5-(methoxymethyl)-2-methylquinolin-8-ol (QO) and 5-((2-hydroxyethoxy)methyl)-2-methylquinolin-8-ol (QOOH) are examined in this work for their ability to adsorb against the corrosion of mild steel (MS) in a molar hydrochloric acid (HCl) media. After the synthesis of these two compounds, we proceeded some analytical methods such as the nuclear magnetic resonance of the proton and the carbon (1H NMR and 13C NMR). Potentiodynamic polarization (PDP), electrochemical frequency modification (EFM), and impedance spectroscopy (EIS) were the methods used in the experimental examination. The results indicated that the inhibitory efficacy of QO and QOOH increases with concentration. Both inhibitors exhibit mixed type behavior, according to the findings of polarization. Following that order was QO's and QOOH's inhibitory efficiencies 93.20% (QO) > 88.84% (QOOH). The Langmuir adsorption model is used in the adsorption process of these two chemicals. A barrier layer encasing the MS was shown to exist by Scanning electron microscope (SEM), energy dispersive X-ray analysis (EDS), atomic force microscopy (AFM), contact angle, and X-ray photoelectron spectroscopy (XPS) were all used in the examination of the surface characterization. The Density functional theory (DFT) findings suggest that inhibitors with electron-accepting capabilities exhibit the strongest interactions with the iron surface.

Novel Corrosion Inhibitor for Carbon Steel in Acidic Solutions Based on α-Aminophosphonate (Chemical, Electrochemical, and Quantum Studies).

α-aminophosphonate (α-AP) is used as a novel corrosion inhibitor for carbon steel. The aggressive media applied in this study are HCl and H2SO4 acid solutions. The findings indicate that the morphology of the α-AP compound is cubic, with particles ranging in size from 17 to 23 μm. FT-IR, 1HNMR, 31PNMR, and 13CNMR analysis confirmed the synthesis of the α-AP molecule. It has been discovered that the compound α-AP plays an important role in inhibiting the corrosion of carbon steel in both HCl and H2SO4 acids. This was identifiably inferred from the fact that the addition of α-AP compound decreased the corrosion rate. It is important to report that the maximum inhibition efficiency (92.4% for HCl and 95.7% for H2SO4) was obtained at 180 ppm. The primary factor affecting the rate at which steel specimens corrode in acidic electrolytes is the tendency of α-AP compounds to adsorb on the surface of steel through their heteroatoms (O, N, and P). This was verified by SEM/EDX results. The adsorption actually occurs through physical and chemical mechanisms via different active centers which are matched with the calculated quantum parameters. In addition, the adsorption of α-AP follows the Langmuir isotherm.

Adsorptive investigation of the anticorrosion properties of natural chrysin on carbon steel in acid–chloride system: combined theoretical and experimental approach

Purpose Owing to the toxicity, biodegradability, and cost of most corrosion inhibitors, research attention is now focused on the development of environmentally benign, biodegradable, cheap, and efficient options. In consideration of these facts, chrysin, a phytocompound of Populus tomentosa (Chinese white poplar) has been isolated and investigated for its anticorrosion abilities on carbon steel in a mixed acid and chloride system. This highlights the main purpose of the study. Design/methodology/approach Chrysin was isolated from Populus tomentosa using column chromatography and characterized using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy. The investigations are outlined based on theory (Fukui indices, condensed density functional theory and molecular dynamic simulation) and experiments (electrochemical, gravimetry and surface morphology examinations). Findings Theoretical evaluations permitted the description of the adsorption characteristics, and molecular interactions and orientations of chrysin on Fe substrate. The interaction energy for protonated and neutral chrysin on Fe (110) were −149.10 kcal/mol and −143.28 kcal/mol, respectively. Moreover, experimental investigations showed that chrysin is a potent mixed-type corrosion inhibitor for steel, whose effectiveness depends on its surrounding temperature and concentration. The optimum inhibition efficiency of 78.7% after 24 h for 1 g/L chrysin at 298 K indicates that the performance of chrysin, as a pure compound, compares favorably with other phytocompounds and plant extracts investigated under similar conditions. However, the inhibition efficiency decreased to 62.5% and 51.8% at 318 K after 48 h and 72 h, respectively. Originality/value The novelty of this study relies on the usage of a pure compound in corrosion suppression investigation, thus eliminating the unknown influences obtainable by the presence of multi-phytocompounds in plant extracts, thereby advancing the commercialization of bio-based corrosion inhibitors.

ODHI: A promising isatin-based corrosion inhibitor for mild steel in hydrochloric acid

The study aimed to investigate the corrosion behavior of mild steel in acidic environments and to evaluate the effectiveness of an ecofriendly inhibitor named 2-oxo-3-((2,4-dimethoxybenzylidene)hydrazono)indolin (ODHI) derived from Isatin. The researchers employed various techniques such as weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy to carry out the experiment in both uninhibited and inhibited 1 M HCl solution at temperatures ranging from 303 to 333 K. The findings revealed that the inhibition efficacy increased with the concentration of ODHI, reaching 94.3% at 0.5 mM in a 1 M HCl solution at 303 K. The results were supported by Density Functional Theory computations, which confirmed the ODHI's corrosion inhibition behavior for mild steel in acidic conditions. The inhibition effect was found to follow the Langmuir isotherm model. Overall, the study demonstrates the potential of ODHI as an effective inhibitor for Mild Steel in acidic environments.

Exploring the Effectiveness of Isatin–Schiff Base as an Environmentally Friendly Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

A recent study has shown that Schiff base OHMHI is an effective inhibitor of the corrosion of mild steel in acidic media. The study utilized weight loss measurements and electrochemical techniques, such as EIS and potentiodynamic polarization, to analyze the corrosion inhibition efficiency of OHMHI. The results of the study show that the presence of OHMHI in the corrosive environment significantly reduced the corrosion rate of mild steel and increased its corrosion resistance. The impedance spectra analysis indicated that OHMHI was adsorbed on the surface of mild steel, providing a protective layer. The potentiodynamic polarization study confirmed the protective role of OHMHI by showing an increase in the passive current density of the mild steel in the presence of OHMHI. The inhibitory efficiency of OHMHI was found to be 96.1%, indicating that it is an effective corrosion inhibitor for mild steel. The study also investigated the optimal conditions for the use of OHMHI as a corrosion inhibitor, with a concentration of 0.5 mM and a temperature of 303 K being chosen. The Langmuir adsorption isotherm concept was used to demonstrate the physical and chemical adsorption of OHMHI on the surface of mild steel. Morphological investigations of the uninhibited and inhibited surfaces of the mild steel specimen were examined using scanning electron microscopy (SEM) analysis. Furthermore, computational investigations using density functional theory (DFT) and experimental data were merged to explore the corrosion inhibition efficiency and mechanism of inhibition. Although the results are promising, further studies are needed to determine the long-term effects of OHMHI on mild steel corrosion and to evaluate its effectiveness under different environmental conditions. Overall, the study highlights the potential of OHMHI as an effective corrosion inhibitor for mild steel in acidic media.

Essential Oil of Origanum vulgare as a Green Corrosion Inhibitor for Carbon Steel in Acidic Medium

In this study, Oregano (Origanum vulgare) leaf essential oil was studied as an environmental-friendly anticorrosion agent for carbon steel in aggressive hydrochloric acid. The corrosion inhibition of O. vulgare was characterized by surface morphology, electrochemical, weight loss, theoretical and computational methods. It was found that the highest inhibition performance of O. vulgare was 85.64% at 2 g/l in 1 M HCl. The results of Langmuir isotherm and adsorption thermodynamics investigation demonstrated that the O. vulgare inhibitor adsorbed on the metal surface by the formation of rigid covalent bonds. The adsorption and inhibition centers of the selected inhibitor were studied by the computational methods, resulting in that the hydroxyl functional groups and benzoyl rings are mainly responsible for the high inhibition efficiency.

Corrosion Behavior of Sensitized AISI 304 Stainless Steel in Acid Chloride Solution.

Corrosion resistance of sensitized austenitic stainless steel (SS) in chloride environments is currently the subject of numerous studies. Most of them are focused on neutral chloride solutions at room temperature and the experiments are carried out on ground stainless steels surfaces. This paper deals with the corrosion behavior of sensitized AISI 304 stainless steel in acid 1 M chloride solution (pH = 1.1) at the temperatures of 20 ± 3 °C and 50 °C. The specimens after sensitization are tested as covered by high-temperature surface oxides ("heat tinted"), and also after their chemical removal to assess the impact of the surface state on corrosion resistance. Potentiodynamic polarization (PP) and exposure immersion test are used as the independent corrosion tests. Microstructure before/after exposure immersion test is evaluated by optical microscopy (OM) and SEM. The results obtained showed that sensitization significantly conditions corrosion regardless of the removal of high-temperature oxides, and the elevated temperature mainly acts as its accelerating factor.

Sunflower-head extract as a sustainable and eco-friendly corrosion inhibitor for carbon steel in hydrochloric acid and sulfuric acid solutions

The inhibition effect of sunflower head-extract (SFHE) for carbon steel in 1 M hydrochloric acid (HCl) and 0.5 M sulfuric acid (H2SO4) solution was studied by weight loss measurement, electrochemical measurements, and ultra-depth three-dimensional microscope. The adsorption/desorption of SFHE from carbon steel surface was studied by the differential polarization curves. The thermodynamic and kinetic parameters were also calculated and discussed. The results show that SFHE is an excellent inhibitor in 1 M HCl and 0.5 M H2SO4, the SFHE exhibits the highest inhibition efficiency of 96.4% and 91.9% at 3 g/L at 298 K in 1 M HCl and 0.5 M H2SO4, respectively. In addition, the inhibition efficiency follows the order: HCl ˃ H2SO4. The adsorption of SFHE on the carbon steel surface obeys the Langmuir adsorption isotherm. All the results reveal that SFHE can be used as a sustainable and environmentally friendly corrosion inhibitor for carbon steel in acid solution in the future.

N-[2-(3-indolyl)ethyl]-cinnamamide synthesized from cinnamomum cassia presl and alkaloid tryptamine as green corrosion inhibitor for Q235 steel in acidic medium

In this work, N-[2-(3-indolyl)ethyl]-cinnamamide (IA) synthesized from tryptamine (TA) and cinnamic acid was evaluated as green corrosion inhibitor for Q235 steel in 0.5 M HCl solution by weight loss tests, potentiodynamic polarization (PDP) curve and electrochemical impedance spectroscopy (EIS). Gravimetric measurements displayed the maximum inhibition efficiencies of TA and IA at 1.0 mM were up to 92.8% and 97.6%, respectively. PDP and EIS studies revealed they could hinder both hydrogen evolution and metal dissolution reactions and that the inhibiting effect was temperature and concentration dependent. The surface analysis of sample was presented through scanning electron microscope (SEM), energy dispersive spectroscopy (EDX) and atomic force microscope (AFM), which indicated the anti-corrosion ability of Q235 steel in hydrochloric acid was enhanced by the inhibitor. The adsorptive behavior of inhibitors including physisorption and chemisorption obeyed Langmuir isotherm. The inhibition mechanism was elucidated by determining the potential of zero charge (Epzc) at solid/liquid interface. Quantum chemistry calculation provided a theoretical estimate of the reactivities of TA and IA as corrosion inhibitors to ascertain the correlation between the inhibition efficiency and molecular structures. Results of molecular dynamics (MD) simulations confirm that IA shows better inhibitive performance due to higher interaction energy (– 79.1 kJ mol−1 for TA and – 144.16 kJ mol−1 for IA).

Anticorrosive properties of green-synthetized benzylidene derivatives for mild steel in hydrochloric acid: An experimental study combined with DFTB and molecular dynamics simulations

Two benzylidene derivatives anisaldehyde-cyanoguanidine imine (CMBG) and p–dimethylaminobenzaldehyde-TRIS imine (DBHP) were prepared according to the 12 Principles of Green Chemistry. They were evaluated as corrosion inhibitors for 1020 mild steel in acidic media (HCl 1 mol L–1) by gravimetric and electrochemical measurements and reached 82 and 92% anticorrosive efficiency, respectively, at 2.20 mmol L-1. A comprehensive theoretical study was carried out using Density-Functional Based Tight Binding (DFTB) and molecular dynamics (MD) simulations. Electrochemical results indicated that inhibitors had a robust inhibitive effect on the corrosion process, significantly increasing the polarization resistance of the working electrode while reducing both cathodic and anodic corrosion reactions. Physical-chemical calculations indicated the formation of a protective multilayer and that physical–chemical adsorption governed the inhibition process. AFM and SEM with EDX analyses depicted a smoother surface in the presence of the organic molecules, pointing to the formation of a protective barrier. DFTB calculations revealed that inhibitor molecules formed covalent bonds with iron atoms, which was confirmed by the Projected Density of States (PDOS) of adsorbed systems.

Phytochemical Constituent and Anti-corrosion Properties of the Root Extract of Phyllanthus mellerianus (Nvo-nkwu) Plant on Mild Steel in 1.5M HCl Medium

The research reports on the phytochemical constituents and anti-corrosion properties of the root extract of Phyllanthus mellerianus on mild steel in 1.5M HCl. The powdered root was extracted with ethanol and concentrated with a rotary evaporator. The phytochemical constituents’ were achieved through GC-MS, FTIR and wet analysis. The anticorrosion properties were investigated via weight loss, hydrogen evolution techniques, and SEM analysis. The phytochemical investigation reveals the presence of tannins, flavonoids, phenols, and terpenoids at reasonable percentages. At different temperatures of 303K, 313K, and 323K, the inhibition efficiency, enthalpy, entropy, activation energy, Gibbs free energy, and adsorption isotherms were extrapolated with some models. The inhibition efficiency increased with an increase in the concentration of the extract, an indication of the inhibitive property of the root extract. This was supported through the extrapolation of Gibbs free energy, activation energy, enthalpy, and entropy change. The thermodynamic variable shows that the mechanism of inhibition was physisorption, whereas the kinetics study confirmed a first-order kinetic on the corrosion of mild steel in hydrochloric acid. The values of the linear regression R2 confirm the inhibitive impact of the root extract on mild steel in an acid medium. The presence of the heteroatoms N, O, and S in the root extracts of Phyllanthus mellerianus has been attributed to their inhibitory effectiveness.

Survival Strategies of Mangrove (Ceriops tagal (perr.) C. B. Rob) and the Inspired Corrosion Inhibitor

Corrosion is ubiquitous, inevitable, and very common in our daily lives; it has been one of the most significant challenges and needs to be addressed for the development of modern society. Corrosion-resisting strategies found in nature have been promising for many halophytes surviving in marine tidal zones facing high salinity and humidity. Among the halophytes, mangroves have developed a lot of functions to deal with such extreme conditions that could provide novel inspirations for the fabrication of engineering materials, especially for materials resisting corrosion. In this study, we first investigated two survival strategies of mangroves, namely, functional salt-secreting and mangrove tannin composite. Salt-secreting realized by mangrove salt glands could make mangroves excrete excessive salt and avoid harmful effects. On the other hand, mangrove tannins existing in large quantities in mangrove bark could help the mangroves survive some marine bacteria. Inspired by the functional mangrove tannins, we developed a corrosion inhibitor to protect Q235 carbon steel in acid 3.5 wt% NaCl solution. Furthermore, we found that the mangrove-inspired corrosion inhibitor could be adsorbed at the metal–solution interface, functioning as a cathodic inhibitor with 60.51% anti-corrosion efficiency.

Determination of the Durability of Polyurethane Coating on Mild Steel in Various Soil Media

In this paper, effort has been made to determine the durability of polyurethane coating on mild steel in acid, alkaline and neutral soil. A total of 42 mild steel coupons were used. Out of the 42 coupons, 21 were coated with polyurethane and the remaining 21 were left uncoated. Acid soil (pH = 4.5), Alkaline soil (pH =13.5) and neutral soil (pH = 6.8) were used as the test media. Seven each of the coated and uncoated coupons were buried in each soil media. On weekly basis, one coated and one uncoated coupon were withdrawn from each of the soil media and reweighed. The durability of the coating in each soil media was calculated using a proposed model. From the results obtained, the durability of polyurethane coating was found to be 7.0yrs, 4.5yrs and 2.9yrs in neutral, acid and alkaline soil respectively.

Corrosion protection of carbon steel in acidic media by expired bupropion drug; experimental and theoretical study

The effects of expired bupropion on the corrosion protection of carbon steel in hydrochloric acid (1.0 M) and sulfuric acid (0.5 M) solutions were examined by Fourier transform infrared (FTIR) spectroscopy, Tafel polarization and electrochemical impedance spectroscopy (EIS). Bupropion concentrations in both acid solutions were raised, which improved corrosion prevention. Bupropion was a mixed inhibitor because it retarded the anodic and cathodic processes, as indicated by polarization data. The inhibition efficiency decreased with the increasing temperature from 25 to 55 °C. In the presence of bupropion, the activation energies of corrosion in both acid solutions increased. The thermodynamic quantities were deduced from the influence of temperature on the corrosion process of carbon steel in both acid media. Bupropion adsorption on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes consistent with the results arising from impedance measurements. FTIR spectroscopy showed the active sites of bupropion molecule during adsorption on the alloy surface. The theoretical study and molecular dynamics simulation of bupropion was done by a density functional theory (DFT) approach to realize the effects of molecular structure on the inhibitive action of bupropion.

Inhibiting Effect of Natural Plant Leaves Extract Used as Green Corrosion Inhibitor for Mild Steel in Acidic Media

Abstract: Inhibition of corrosion of mild steel in hydrochloric acid by natural plant leaves extract of of Bahunia Varigata (Aapta), Azadirachta Indica (Neem), Pongamia Pinnata (Karanj), Santalum Album (Sandal Wood) and Astonia Scholaris (Saptparni) has studied using weight loss measurement. It was, found that the leaves extract act as a good corrosion inhibitor for mild steel in all concentrations of the extract. The inhibition action depends on the concentration of the leaves extract in the acid solution. Results for weight loss measurements indicate that inhibition efficiency increase with increasing inhibitor concentration. Extract of natural plants is one of the most important metallic corrosion inhibitors. They are readily available, nontoxic, environmentally friendly, biodegradable, highly efficient, and renewable. Several organic compounds with heteroatom such as N, O, S and P present in the plant extracts are, adsorbed directly onto the metals surface through polar atoms and thereby forming the protective layer. Plants represent a class of interesting source of compounds currently being, explored for use in metal corrosion protection in most systems, as possible replacement of toxic synthetic inhibitors. This paper discusses the different types of natural green plant leaves extract inhibitors for corrosion control of mild steel in acid medium. Keywords: Corrosion, Inhibition, carbon steel, Weight loss and natural plant leaves extract.

Особенности коррозии и ингибиторной защиты сталей в растворах кислот, содержащих соли железа (III). Обзор

A critical analysis of literature data on corrosion of steels in solutions of mineral acids containing Fe(III) salts and the possibility of inhibitory protection of steels in these environments has been carried out. The accumulation of Fe(III) salts in acid solutions during their operation at metallurgical, oil and gas enterprises, objects of housing and communal services is a result of dissolution of mineral deposits, scale, thermal scale, and rust containing Fe (III) compounds in them. In addition, additional oxidation of Fe(II) salts in acid solutions to Fe(III) compounds is possible. The effect of the redox potential, determined by the ratio of the content of Fe(III) and Fe(II) cations in them, as well as mobility of Fe(III) cations, on the corrosivity of the systems under consideration was examined. The reasons for the accelerating and retarding action of Fe(III) salts on corrosion of steels in acidic media were analyzed. Modern concepts of the mechanism of corrosion of steels in these environments are discussed. The low efficiency of the inhibitory protection of steels in mineral acids containing Fe(III) salts is demonstrated. It is noted that it is possible to increase the protective effect of some corrosion inhibitors (CI) in these environments by reducing their overall aggressiveness. It can be achieved by introducing H3PO4 into them, which is capable of binding Fe(III) into strong complexes that have a lower oxidizing capacity than Fe(III) aqua complexes and mobility in an aggressive environment. The CI used in an aggressive environment must be effective in slowing down not only the cathodic reduction of protons and anodic ionization of iron, but also significantly suppress reduction of Fe(III) cations, which is realized with the diffusion control. These requirements are met by composite CI based on triazoles, which in H2SO4 + H3PO4 and HCl + H3PO4 solutions containing Fe(III) salts are effective in slowing down the corrosion of low-carbon steel.

Experimental and theoretical studies of carbon steel corrosion protection in phosphoric acid solution by expired lansoprazole and rabeprazole drugs

The effects of expired lansoprazole and rabeprazole on the corrosion protection of carbon steel in phosphoric acid (3.0 ​M) solution were examined by Tafel polarization and electrochemical impedance spectroscopy (EIS). Lansoprazole and rabeprazole concentrations (0.5, 1.0, 5.0 and 10 ​mM) in acid solution were raised, which improved corrosion prevention. Both lansoprazole and rabeprazole as the mixed inhibitors retarded the anodic and cathodic processes, as indicated by polarization data. With the increasing temperature in the range of 25–55 ​°C, the inhibition efficiency drops from 92.9% to 69.3% for lansoprazole and from 94.8% to 74.2% for rabeprazole. The major decrease in the inhibition efficiency with ascending temperature proved the physisorption of the drugs. The activation energies for carbon steel corrosion in H3PO4solution were enhanced from 41.6 ​kJ ​mol−1 to 81.9 ​kJ.mol−1and 85.9 ​kJ ​mol−1 for lansoprazole and rabeprazole, respectively. The influence of temperature on the corrosion process of carbon steel in the acid medium was used to derive the thermodynamic quantities of corrosion. The adsorption of both lansoprazole and rabeprazole on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes that were consistent with the results arising from impedance measurements. The theoretical study of both lansoprazole and rabeprazole was done by a density functional theory (DFT) approach to realize the effects of molecular structure on their inhibitive action. Both lansoprazole and rabeprazole contain a higher EHOMO, a lower ELUMO and a lower energy gap than some inhibitors earlier reported as good corrosion inhibitors in the literature.

Role of Organic and Eco-Friendly Inhibitors on the Corrosion Mitigation of Steel in Acidic Environments-A State-of-Art Review.

Steel has versatile application in chemical, structure and construction industries owing to its mechanical properties. However, it is susceptible to corrosion in acid environments. Thus, it requires to protect the steel from corrosion. Different types of corrosion resistance steel, coatings and inhibitors are developed to mitigate the corrosion, but, inhibitor is the best remedies to control the corrosion of steel in acid condition. Moreover, organic and green inhibitors used in acid condition for descaling, acid pickling, pipelines, boiler tubes and oil-wells. Organic inhibitors reduce the dissolution of steel in acid but, it is hazardous, expensive and needs expertise to synthesize the inhibitor. Therefore, there is utmost required to study and compile the latest research about the eco-friendly corrosion inhibitors, which showed more than 90% corrosion inhibition efficiency. In the present study, I have reviewed the state-of-arts, and compile the latest development in organic and eco-friendly corrosion inhibitor used in acid environment as well as suggested about the future scope and role of green inhibitor for sustainable society, which is economical, less hazardous and readily available from the natural sources.