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Corrosion experiments and theoretical calculations were performed to investigate the inhibition mechanism of indazole (IA) and 5-aminoindazole (AIA) for copper in NaCl solution. The ...results obtained from weight loss and electrochemical experiments are in good agreement, and reveal that these compounds are high-efficiency inhibitors with inhibition efficiency order: AIA>IA, which was further confirmed by field emission scanning electronic microscope (FESEM) observation. Besides, the quantum chemical calculations and molecular dynamics (MD) simulation showed that both studied inhibitors are adsorbed strongly on the copper surface in parallel mode. The adsorption of these molecules on copper substrate was found to obey Langmuir isotherm.
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•NCDs effectively suppress copper corrosion in aggressive acid medium.•NCDs can be designated as a modest cathodic-type inhibitor.•The NCDs–adsorption film involves both physisorption ...and chemisorption.
Researchers recent reported that N-doped carbon dots (NCDs) effectively inhibit steel corrosion in HCl solution, whereas the action mechanism is still uncertain to date. Herein, novel NCDs have been prepared using a facile hydrothermal method. Combining electrochemical, weight loss, and micromorphology techniques, the resultant NCDs were found to effectively suppress copper corrosion in aggressive H2SO4 medium. NCDs–adsorption film was formed on copper substrate as a barrier that could prevent transportation of corrosive particles. The relevant anticorrosion mechanism of NCDs was proposed in detail, which could provide powerful guidance to design and synthesis new nanomaterials for metal protection from corrosion.
•Four allyl imidazolium-based ionic liquids are used as green inhibitors for copper corrosion in sulfuric acid.•The inhibition efficiencies of the investigated inhibitors increase with the augment of ...alkyl chain length attached to the imidazolium ring.•The order of inhibition ability obtained from EIS is in perfect agreement with the polarization results.•Theoretical calculations provide favorable support for the experimental data.
In this work, four allyl imidazolium-based ionic liquids (ILs) with various length of alkyl chains were developed for the corrosion inhibition of copper in 0.5M sulfuric acid. Electrochemical techniques, morphological characterization, theoretical caculations were combined to investigate the inhibition performance and mechanism. The results show that corrosion circumstance of copper in sulfuric aqueous solution is efficiently inhibited by these ILs. Their favorable performance is ascribed to formation of ILs-adsorption films, which follow the Langmuir adsorption isotherm. Besides, the inhibition efficiencies of the investigated inhibitors increase with the augment of alkyl chain length attached to the imidazolium ring.
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•Two novel long-chain indazole derivatives were synthesized and then fabricated on copper surface.•DDIA-SAMs containing double alkyl-chain tails harbor more superior inhibition ...performance for copper corrosion than DI-SAMs.•The inhibition mechanism was elucidated via DFT calculation.
Two novel long alkyl-chain indazole derivatives namely, 1-dodecyl-1H-indazole (DI), N,1-didodecyl-1H-indazol-5-amine (DDIA), were synthesized and fabricated on copper surface. Comprehensive characterizations were used to evaluate the appearance and structural properties of studied SAMs, implying a more stable and hydrophobic film of DDIA than IA. The anticorrosion ability of the SAMs was investigated by electrochemical methods allied to an immersion test, which suggest that DDIA-SAMs harbor more superior inhibition performance than IA ones. Besides, Fukui functions indicates that N2 and N10 in DDIA molecule are likely to form coordinate bonds with Cu atoms, whereas N2 in DI is the active site during absorption process.
•OMIMBr and AOIMBr are modest cathodic inhibitors for mild steel in 0.5 M H2SO4.•AOIMBr shows better corrosion inhibition due to the allyl electron-donating group.•Inhibitor mainly physically adsorbs ...on steel surface via positively charged N atom.•The adsorption of inhibitor molecules obeys El-Awady thermodynamic–kinetic model.
The inhibition performance and mechanism of 1-octyl-3-methylimidazolium bromide (OMIMBr) and 1-allyl-3-octylimidazolium bromide (AOIMBr) for the corrosion of mild steel in 0.5M H2SO4 were investigated using weight loss method, electrochemical measurements, scanning electron microscope (SEM) and quantum chemical calculation. The results revealed that OMIMBr and AOIMBr acted as modest cathodic inhibitors, and due to the electron-donating effect of allyl group, AOIMBr showed better inhibitive performance. The adsorption of both inhibitors on steel surface obeyed El-Awady thermodynamic–kinetic model, thus the thermodynamic and kinetic parameters were calculated and discussed. Moreover, theoretical calculation was used to investigate inhibition mechanism of studied inhibitors.
As a vital derivative of graphene, graphene oxide (GO) is widely applied in various fields, such as transparent electrodes, solar cells, energy storage, and corrosion protection due to the large ...specific surface area and abundant active sites. However, compared with graphene, the application of GO has been less reported in metal corrosion protection field. Therefore, in our study, 3-aminobenzenesulfonic acid was selected to combine with oligoanilines to fabricate the GO-based sulfonated oligoanilines coatings for marine corrosion protection application. The obtained composite coatings were covered on the surface of Q235 steel, which is one of the most important structural marine materials. Fourier transform infrared spectra were utilized to prove the existence of different bonds and functional groups of aniline trimer and sulfonated aniline trimer (SAT). Scanning electron microscopy was applied to verify the combination of GO and SAT. What’s more, transmission electron microscopy was applied to observe the surface appearance of the obtained GO–SAT composite material. Besides, the results of electrochemical measurements performed in 3.5 wt % NaCl solution showed excellent corrosion-protective properties of GO/SAT-coated epoxy resin with a dosage of 10 mg of GO compared with the pure epoxy resin. Moreover, the enhancement of surface hydrophobic property, to some extent, is in favor of preventing the absorption of corrosive medium and water molecules revealed by contact angle test. The addition of GO can make the diffusion pathway of the corrosive medium longer and more circuitous, while SAT has displayed excellent solvent solubility while maintaining corrosion-protective properties similar to those of polyanilines so that the corrosion-protective properties of the modified coatings improve significantly due to the synergistically enhanced corrosion protection of GO and SAT.
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Food flavors of 2-isobutylthiazole (ITT) and 1-(1,3-Thiazol-2-yl)ethanone (TEO) for the corrosion inhibition of X65 steel in H2SO4 were studied by electrochemical methods, atomic ...force microscopy (AFM), scanning electron microscopy (SEM) and theoretical calculations. Electrochemical experiments show that ITT and TEO can effectively inhibit the corrosion of cathode and anode of X65 steel, and they are mixed-type corrosion inhibitors. Surface topography analysis (SEM and AFM) also visually demonstrate that ITT and TEO form an effective barrier film on the X65 steel surface to isolate the corrosive medium. Theoretical calculations profoundly explain the inhibition mechanism of ITT and TEO at the molecular level. In addition, the adsorption behavior of ITT and TEO on the surface of X65 steel is consistent with Langmuir isotherm adsorption. The results of experimental and theoretical studies have shown that the inhibition effect of TEO is better than ITT for X65 in 0.5 M H2SO4.
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Conventional organic and inorganic corrosion inhibitors are noxious and hazardous to living organisms and the environment. Therefore, the use of plant extracts as potential corrosion ...inhibitors for metals has attracted considerable attention because these compounds are renewable and can have low toxicity, mainly when derived from edible plant species. Here, we prepared Atriplex leucoclada extract (ALE, 0–8g/L) and tested its effectiveness as an eco-friendly copper corrosion inhibitor in 1M HCl using several characterisation techniques, such as potentiodynamic polarisation experiments at the open-circuit potential, electrochemical impedance spectroscopy, and surface morphology. Adsorption isotherm modelling based on the Langmuir monolayer adsorption model revealed that the antioxidant flavonoids and polyphenolic compounds in ALE adsorb on the surface of copper and act as mixed-type inhibitors to reduce copper corrosion. Notably, the use of ALE resulted in a high (91.5%) inhibition efficiency at room temperature. Our results demonstrate the potential of ALE as a corrosion inhibitor for copper in acidic media and enrich knowledge regarding the use of plant extracts as green corrosion inhibitors.
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•Three triazole derivatives as corrosion inhibitors were theoretically investigated.•Quantum chemical calculations and Monte Carlo simulations were performed.•Quantitative structure ...activity relationship (QSAR) approach has been used.•Theoretical conclusions are validated by the consistency with experimental findings.
Corrosion inhibitive performance of 4-chloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (CATM), 4-fluoro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (FATM), and 3,4-dichloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (DATM) during the acidic corrosion of mild steel surface was investigated using density functional theory (DFT). Quantum chemical parameters such as the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), Mulliken charges, hardness (ξ), dipole moment (μ), and the fraction of electrons transferred (ΔN), were calculated. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of above-mentioned descriptors was performed to characterize the inhibition performance of the studied molecules. Furthermore, Monte Carlo simulation studies were applied to search for the best configurational space of iron/triazole derivative system.
Micrometer‐sized electrochemical capacitors have recently attracted attention due to their possible applications in micro‐electronic devices. Here, a new approach to large‐scale fabrication of ...high‐capacitance, two‐dimensional MoS2 film‐based micro‐supercapacitors is demonstrated via simple and low‐cost spray painting of MoS2 nanosheets on Si/SiO2 chip and subsequent laser patterning. The obtained micro‐supercapacitors are well defined by ten interdigitated electrodes (five electrodes per polarity) with 4.5 mm length, 820 μm wide for each electrode, 200 μm spacing between two electrodes and the thickness of electrode is ∼0.45 μm. The optimum MoS2‐based micro‐supercapacitor exhibits excellent electrochemical performance for energy storage with aqueous electrolytes, with a high area capacitance of 8 mF cm−2 (volumetric capacitance of 178 F cm−3) and excellent cyclic performance, superior to reported graphene‐based micro‐supercapacitors. This strategy could provide a good opportunity to develop various micro‐/nanosized energy storage devices to satisfy the requirements of portable, flexible, and transparent micro‐electronic devices.
A new approach for large‐scale fabrication of 2D MoS2 film‐based micro‐supercapacitors is developed via a simple spray painting of MoS2 nanosheets and subsequent laser patterning of the deposited film. The optimized MoS2‐based micro‐supercapacitor exhibits excellent electrochemical performance for energy storage, with a high area capacitance of 8 mF cm−2 and excellent cyclic performance, superior to state of the art carbon‐based micro‐supercapacitors.
