A combined computational & electrochemical exploration of the Ammi visnaga L. extract as a green corrosion inhibitor for carbon steel in HCl solution

Natural-based corrosion inhibitors have gained great research interest thanks to their low cost and higher performance. In this work, the chemical composition of the methanolic extract of Ammi visnaga umbels (AVU) was evaluated by gas chromatography (GC) coupled with mass spectrometry (MS) and applied for corrosion inhibition of carbon steel (CS) in 1.0 mol/L HCl using chemical and electrochemical techniques along with scanning electron microscope (SEM) and theoretical calculations. A total of 46 compounds were identified, representing 89.89% of the overall chemical composition of AVU extract, including Edulisin III (72.88%), Binapacryl (4.32%), Khellin (1.97%), and Visnagin (1.65%). Chemical (Weight loss) and electrochemical (potentiodynamic polarization curves (PPC), and electrochemical impedance spectroscopy (EIS)) techniques revealed that investigated extract can be used as an effective corrosion inhibitor for carbon steel in 1.0 mol/L HCl solution. At a low dose of 700 ppm, the inhibitory action of AVU extract reached an inhibition efficiency of 84 percent. According to polarization tests, the investigated extract worked as a mixed inhibitor, protecting cathodic and anodic corrosion reactions. The EIS test showed that upon the addition of AVU extract to HCl solution, the polarization resistance increased while the double layer decreased. SEM images showed a protected CS surface in the inhibited solution. Quantum chemical calculations by Density Functional Theory (DFT) for the main components confirmed the major role of heteroatoms and aromatic rings as adsorption sites. Molecular dynamics (MD) simulation was used to study the adsorption configuration of the main components on the Fe(1 1 0) surface. Outcomes from this study further confirmed the significant advantage of using plant-based corrosion inhibitors for protecting metals and alloys.     

Evaluation of Allium sativum as corrosion inhibitor for carbon steel in sulphuric acid under hydrodynamic conditions

ABSTRACT

A study on the use of Allium sativum (garlic) as corrosion inhibitor for carbon steel in 0.5?M H₂SO₄ has been carried out in static and dynamic conditions by using potentiodynamic polarization curves and electrochemical impedance spectroscopy at 0, 200, 500, 1000 and 2000?rpm. Inhibitor concentrations included 0, 100, 200, 400, 600, 800 and 1000?ppm. Under static conditions, inhibitor efficiency increases with increasing its concentration up to 400?ppm, but it decreases with a further increase in its concentration. Under dynamic conditions and short testing times, inhibitor efficiency increases with increasing the rotating speed, due to a better inhibitor transfer towards the steel surface. However, for longer testing times, inhibitor efficiency increases only during the first 2?h, and then it decreases with a further increase in time, indicating a desorption of the inhibitor molecules from the steel surface.     

Medicago sativa as a green corrosion inhibitor for 1018 carbon steel in 0.5 M H2SO4 solution

A study on the use of the methanol extract of Medicago sativa as a green corrosion inhibitor for 1018 carbon steel in 0.5?M of sulfuric acid has been carried out by using potentiodynamic polarization curves, electrochemical impedance spectroscopy and gravimetric tests. Testing temperatures were 25°C, 40°C and 60°C. Results showed that M. sativa is a good corrosion inhibitor, with its efficiency increasing with its concentration and with time, but decreasing with the temperature. M. sativa forms a passive film on top of the steel with a passive current density and pitting potential values lower than that for uninhibited solution, and remained on the steel for 8–12?h. This film formed by iron ions and heteroatoms present in OH^? and amine groups from the extract are adsorbed on the steel and form a protective film on to the steel.     

Some natural aqueous extracts of plants as green inhibitor for carbon steel corrosion in 0.5 M sulfuric acid

The inhibiting impact of natural aqueous extracts of some plants such as curcumin, parsley and cassia bark extracts for the corrosion of carbon steel (C-steel) in 0.5 M H₂SO₄ solution was inspected utilizing some techniques such as galvanostatic and potentiodynamic anodic polarization and weight loss measurements. Outcomes indicated that the percentage inhibition efficiency increases with increasing the concentration of the extract due to its horizontal adsorption on the C-steel surface. The process of adsorption is followed by the Temkin isotherm. These natural extracts acted as pitting corrosion inhibitors by shifting the pitting potential to more noble values. The sequence of inhibition efficiency of the natural extracts decreases in the following order: cassia bark extract > parsley extract > curcumin extract. This arrangement is related to the molecular size of the major components of the three natural extracts used.     

Benzalkonium chloride/titanium dioxide as an effective corrosion inhibitor for carbon steel in a sulfuric acid solution

In this study, the corrosion performance of carbon steel samples in 0.5 M sulfuric acid by the addition of novel inhibitors, 200 ppm of (25% and 50%) titanium dioxide nanoparticles in benzalkonium chloride, was thoroughly investigated. Gravimetric measurements, cyclic and linear potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and hydrogen collection by water displacement evaluated inhibition performance. Analogously, TiO₂/ILB (50%), TiO₂/ILB (75%), and ILB inhibitors enhanced corrosion protection with over 80% inhibition efficiency in electrochemical tests. In addition, weight loss and hydrogen collection measurements reached comparable results. According to potentiodynamic polarization curves, inhibitors exhibited dual behavior, but cathodic protection was more predominant. Scanning electron microscopy (SEM) was employed to examine the surface morphology before and after immersion using corrosion tests. The correlation between electronic properties and inhibition efficiencies of tilted inhibitors was determined by simple linear regression. Electronic properties were calculated for neutral and protonated forms using a polarizable continuum model by the DFT method at the B3LYP/6-311+G (d, p) level of theory. The active adsorbed sites of HM1-HM3 on the metal surface were determined by analyzing their corresponding electrostatic surface potentials (ESP). Furthermore, molecular dynamics simulations were performed to illustrate the most conceivable adsorption configuration between the inhibitors and metal surfaces.     

Cocos nucifera L. water as green corrosion inhibitor for acid corrosion of aluminium in HCl solution

<正>The ability of Cocos nucifera L.water(CW) as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique.CW shows significant inhibition as corrosion inhibitor,with 93%efficiency at the highest concentration of the inhibitor.The inhibitive action is attributed to the adsorption of the inhibitor molecules on metal surface following Langmuir adsorption isotherm.     

4-phenyl-decahydro-1H-1,5-benzodiazepin-2-one as novel and effective corrosion inhibitor for carbon steel in 1 M HCl solution: A combined experimental and empirical studies

The heterocyclic system, namely 4-phenyl-decahydro-1H-1,5-benzodiazepin-2-one (POBZ) was inspected as a corrosion inhibitor of carbon steel (CS) in a 1 M HCl medium through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization measurements (PDP), and scanning electron microscopy (SEM). The experimental data indicate that the inhibiting action augments with augmenting POBZ amount and reduces with augmenting temperature. The inhibiting action efficiency of 90.98% is obtained with 0.001 M at 303 K. The potentiodynamic polarization (PDP) results mentioned that the POBZ is of mixed type. The adsorption of POBZ on the CS followed Langmuir isotherm. SEM exams affirmed that the steel surface is smooth in presence of POBZ. In light of the calculations of density functional theory (DFT) and molecular dynamics simulation, the mechanism of POBZ inhibitory activity was addressed.     

Biochemical response of Cupressus sempervirens to cement dust: Yields and chemical composition of its essential oil

The effects of cement dust on the yield and chemical composition of the essential oil were investigated in Cupressus sempervirens. Exposure to cement dust resulted in a significant increase in the essential oil yields. Significant factory distance-related changes in qualitative and quantitative composition of the essential oil were observed. Increasing pollution with dust increased the content of monoterpene hydrocarbons concomitant to increase of α-pinene, suggesting a redirection of the secondary metabolism of C. sempervirens towards biosynthesis of monoterpenes. In contrast, oxygenated monoterpenes and sesquiterpene hydrocarbons were strongly reduced. These results provide an overall picture of the different responses of monoterpenes and sesquiterpenes to air pollution caused by cement dust. They also reveal the suitability of using C. sempervirens in the creation of green areas around cement factories and encourage the use of dusted plants as potential source of valuable natural products.     

Experimental and DFT analysis of onion peels for its inhibition behavior against mild steel corrosion in chloride solutions

Natural materials are good options for being used as inhibitors due to their high biodegradability, reasonable cost, easiness in use and high efficiency. In this regard, waste natural materials are very useful because they have all the properties of natural materials and easily available at very low cost (almost free). This work reports a similar kind of waste natural materials namely onion peels. The water extract of onion peels (WEOP) is characterized by UV–vis spectroscopy (UVS) and FTIR spectroscopy (FTIS). WEOP is tested for corrosion inhibition of mild steel (MS) in 1 M NaCl by various techniques like typical weight loss measurements (WLM), open circuit potential (OCP) curves, Tafel polarization (TP) curves, electrochemical impedance spectroscopy (EIS) and surface scanning microscopy (SEM). The maximum inhibition of mild steel corrosion is 90% (WLM). The reason of inhibition based on experimental analysis is proposed as adsorption of extract molecules on MS, which is found true in SEM images and Langmuir isotherm study. The WEOP is also examined by density functional theory principles, which recommends that the extract molecules can be easily adsorbed on MS and can stop corrosion of MS in NaCl solutions. Based on investigation, a schematic is introduced for compact explanation.     

Essential oil of Salvia aucheri mesatlantica as a green inhibitor for the corrosion of steel in 0.5 M H2SO4

Essential oil of aerial parts of Salvia aucheri Boiss. var. mesatlantica was obtained by hydrodistillation and analyzed by GC and GC/MS. The oil was predominated by camphor (49.59%). The inhibitory effect of this essential oil was estimated on the corrosion of steel in 0.5 M H₂SO₄ using electrochemical polarization and weight loss measurements. The corrosion rate of steel is decreased in the presence of natural oil. The inhibition efficiency was found to increase with oil content to attain 86.12% at 2 g/L. Polarization curves revealed that the oil of S. aucheri mesatlantica acts as mixed type inhibitor with a strong predominance of anodic character. The temperature effect on the corrosion behavior of steel in 0.5 M H₂SO₄ without and with the inhibitor at 2 g/L was studied in the temperature range from 303 to 343 K, the associated activation energy have been determined. The adsorption of oil on the steel surface was found to obey Langmuir’s adsorption isotherm.     

Use of an amide-type corrosion inhibitor synthesized from the coffee bagasse oil on the corrosion of Cu in NaCl

An amide, namely N-[2-[(2-hydroxyethyl) amino] ethyl]-amide, extracted from the fatty acids contained in the coffee bagasse, has been investigated as a possible green corrosion inhibitor for copper in 3.5% NaCl by using potentiodynamic polarization curves and electrochemical impedance spectroscopy measurements. Results were complemented by detailed scanning electronic microscopy, FTIR and gas chromatography studies. Results have shown that N-[2-[(2-hydroxyethyl) amino] ethyl]-amide is a good, mixed type of corrosion inhibitor, with an efficiency that increases with its concentration but it decreases with a rise in the temperature. It adsorbs chemically onto the copper surface by following a Langmuir type of adsorption isotherm.     

A surprising method for green extraction of essential oil from dry spices: Microwave dry-diffusion and gravity

Without adding any solvent or water, we proposed a novel and green approach for the extraction of secondary metabolites from dried plant materials. This "solvent, water and vapor free" approach based on a simple principle involves the application of microwave irradiation and earth gravity to extract the essential oil from dried caraway seeds. Microwave dry-diffusion and gravity (MDG) has been compared with a conventional technique, hydrodistillation (HD), for the extraction of essential oil from dried caraway seeds. Essential oils isolated by MDG were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained by HD, but MDG was better than HD in terms of rapidity (45min versus 300min), energy saving, and cleanliness. The present apparatus permits fast and efficient extraction, reduces waste, avoids water and solvent consumption, and allows substantial energy savings.     

Study of electropolishing inhibition of steel using natural products as a green inhibitor in ortho-phosphoric acid

ABSTRACT

Anodic inhibition of steel in 8?mol?L^?1 H₃PO₄ was investigated in the absence and presence of different concentrations of extracts of Lawsonia inermis. An experimental measurement, including galvanostatic polarization studies, was done. The anodic corrosion rate and the inhibition efficiencies of the extract were calculated. The results obtained show that the inhibition was found to increase with increasing concentration of Lawsonia inermis extract. The inhibition actions of extracts are discussed on the basis of adsorption of Lawsonia inermis at the steel surface. Theoretical fitting of different isotherms were tested to clarify the nature of adsorption. Polarization curves revealed that Lawsonia inermis inhibitor acts as a corrosion inhibitor. The activation energy (E_a) as well as other thermodynamic parameters (ΔH*, ΔS*, ΔG*) for the inhibition process were calculated. These thermodynamic parameters show strong interaction between the inhibitor and the steel surface. The scanning electron microscope analysis study confirmed the adsorption of inhibitor molecules on the steel surface. The social organization and morphology of the extract were characterized by Fourier transform infrared spectroscopy.     

Xanthione: A new and effective corrosion inhibitor for mild steel in sulphuric acid solution

The adsorption and inhibition effect of xanthione (XION) on mild steel in 0.5 M H₂SO₄ at 303–333 K were studied using gravimetric and UV–visible spectrophotometric methods. The results obtained show that XION acts as an effective corrosion inhibitor for mild steel in sulphuric acid and inhibition efficiency reaches 98.0% at a very low inhibitor concentration of 10 μM. Inhibition efficiency was found to increase with increase in XION concentration but decreased with temperature suggesting physical adsorption mechanism. Arrhenius law and its transition equation lead to estimate the activation parameters of the corrosion process. XION inhibits the corrosion of mild steel effectively at moderate temperature and adsorbs according to the Langmuir isotherm. Thermodynamic parameters governing the adsorption process have been calculated and discussed. The UV–visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a XEN–Fe complex. Attempt to correlate the molecular structure to quantum chemical indices was made using density functional theory (DFT).     

Mild steel corrosion inhibition by acid extract of leaves of Hibiscus sabdariffa as a green corrosion inhibitor and sorption behavior

A new corrosion inhibitor, namely acid extract of leaves of Hibiscus sabdariffa, has been synthesized, and its inhibiting action on the corrosion of mild steel in acidic bath (1.2 N HCl and 1.2 N H₂SO₄) has been investigated by corrosion-monitoring techniques. The results of the present study show that this compound has decent inhibiting property for mild steel corrosion in 1.2 N H₂SO₄ than 1.2 N HCl. Four sorption isotherms are tested for the data, namely Langmuir, Frumkin, Florry–Huggins, and Langmuir–Freundlich isotherms; of these the Langmuir isotherm fits the data well having correlation coefficient over 0.99 in both the acid environments.     

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 E_HOMO, a lower E_LUMO and a lower energy gap than some inhibitors earlier reported as good corrosion inhibitors in the literature.     

Extract sarampa wood (Xylocarpus Moluccensis) as an eco-friendly corrosion inhibitor for mild steel in HCl 1M

Plant extracts are currently being used as eco-friendly corrosion inhibitors. In this study, the inhibitive performance of Xylocarpus Moluccensis extract (XME) was used as an eco-friendly corrosion inhibitor for the first time. The extract was studied using electrochemical measurement on mild steel in 1M HCl. Results from FIR and phytochemical confirmed that Xylocarpus Moluccensis extract contains compound hydroxyl group, phenolic, and flavonoid content which can be used as a corrosion inhibitor. The inhibition efficiency was determined using Tafel polarization and electrochemical impedance spectroscopy and showed 68% efficiency in 500 ppm. Langmuir adsorption isotherm was used to determine the adsorption mechanism of XME. Surface characterization (AFM) was also used to study the surface morphology of protective film inhibitors.     

Olive leaf extract as a green corrosion inhibitor of reinforced concrete contaminated with seawater

In reinforced concrete, a high alkaline medium, steel is commonly protected by formation a passive oxide film. Nevertheless, contamination with chlorides or carbonation causes the deterioration of protective film and the initiation of pitting corrosion. Hence, the need to enrich the fresh concrete solution with a good corrosion inhibitor. In accordance with green chemistry to evade toxicity and minimize waste, we have chosen to replace the usual inhibitors with an alternative not only ecological but also derived from biological wastes, in a perspective of circular economy emphasizing that waste can offer important compounds at an affordable price and easily available. In this context this work seeks to valorize the dried olive leaves extract as an inhibitor in alkaline chloride solution (pH 13). The targeted plant was grown in arid zones of Saudi Arabia and their leaves are usually disposed of as solid waste or animal feed. Four extraction solvents of different polarities were used; methanol, ethyl acetate, dichloromethane and hexane. The anticorrosive activity was performed using different electrochemical techniques; polarization curves, electrochemical impedance spectroscopy and Mott-Schottky analyses. The polarization studies proved that extract from olive leaves is a mixed type inhibitor in a solution of NaOH (0.1 M) + NaCl (0.5 M),with a predominant anodic effectiveness. The best inhibition of 91.9% is provided with methanol extract. GC–MS analysis showed the presence of compounds containing the heteroatoms N and O with the π electrons which are responsible for the corrosion inhibition activity. The olive leaves have been found to be high in phenol and flavonoid content. Inhibition efficiency of the olive leaves extracts increases with the polarity of extraction solvents but also it appears that it depends on another factors.     

Utilization of biowaste as an eco-friendly biodegradable corrosion inhibitor for mild steel in 1 mol/L HCl solution

This report focuses on the application of a biodegradable biowaste [human hair-(HHR)], to produce a mild steel corrosion inhibitor. The performance of HHR extract in inhibiting metallic corrosion in 1 mol/L HCl was investigated. The analysis of the metal corrosion behavior using electrochemical and weight loss techniques revealed that HHR exhibits an efficient corrosion-mitigating effect via adsorption on the metal surface following a Langmuir isotherm. Tafel-plot results revealed the mixed-mode corrosion protection behavior of HHR. Surface analysis using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and Fourier transform infrared (FT-IR) spectroscopy provided evidence for the precipitation of a protective HHR film on the metal surface.     

An investigation of carbon steel corrosion inhibition in hydrochloric acid medium by an environmentally friendly green inhibitor

The inhibition effect of polyphenols extracted from olive mill wastewater (PP) on carbon steel in 1.0 M HCl solution was studied. Inhibition efficiency of PP was carried out by using chemical (weight loss method) and electrochemical techniques [potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)]. The effect of temperature and immersion time on the corrosion behavior of carbon steel in 1.0 M HCl with addition of an extract was also studied. The results show that PP acts as a very good inhibitor, and the inhibition efficiency increases with the concentration of PP and decreases with rising temperature. Polarization curves show that PP behaves as a mixed-type inhibitor in hydrochloric acid. Data, obtained from EIS measurements, were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model; a constant phase element has been used. EIS shows that charge-transfer resistance increases and the capacitance of double layer decreases with the inhibitor concentration, confirming the adsorption process mechanism. The activation energy as well as other thermodynamic parameters for the inhibition process were calculated. The adsorption of PP obeys the Langmuir adsorption isotherm.