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In the pickling industry, corrosion can deteriorate the quality of equipment and supplies, causing financial losses and safety threats. Therefore, it has become crucial to develop novel corrosion inhibitors that are bioactive, efficient, affordable, medium-acid soluble, and ecologically safe to protect mild steel during industrial cleaning. In this work, three newly synthesized imidazo[1,2-a]pyridine derivatives were characterized by various spectroscopic techniques. The studied compounds were evaluated as corrosion inhibitors for mild steel in 1 M HCl medium using weight-loss, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. The imidazopyridine derivatives showed excellent anticorrosion performance, their inhibitory efficiencies increased with the increase of inhibitors concentration and evolved in the following order: Imd2 (98.1%) >Imd1 (96.5%) >Imd3 (95.3%). This order was justified by the presence of two chlorine atoms in the ortho position of the Imd2 structure. The three Imd derivatives obeyed to the Langmuir isotherm, this explained the formation of an organic monolayer on the steel surface indicated by the scanning electron microscope (SEM) and the atomic force microscope (AFM). In addition, density functional theory (DFT) and molecular dynamics (MD) simulations were performed to reveal the anticorrosion mechanism. The present study illustrates at the microscopic level how mild steel resists corrosion and ensures the safety of pickling. [ABSTRACT FROM AUTHOR]

The mutually corroborated density functional theory (DFT) and molecular dynamics (MD) simulation methodology were employed to evaluate the inhibition performance of three thiourea derivatives (Inh1, Inh2, and Inh3) on carbon steel corrosion. Experimental results have shown that the corrosion rate follows the order: Inh3 > Inh2 > Inh1. Quantum chemical descriptors such as the frontier orbital energies ( E HOMO and E LUMO ), the energy gap between E LUMO and E HOMO (Δ E ), dipole moment (μ), and Fukui index have been calculated and discussed. Some significant factors such as solvent, temperature, and coverage have been considered when investigating the adsorption of aforementioned thiourea derivatives on Fe(1 1 0) surface. Our results provide important atomic/molecular insights into the anticorrosive mechanism of inhibitor molecules, which could help in understanding the organic-metal interface and designing more appropriate organic corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Al-air battery is a kind of chemical battery exhibiting high theoretical energy density. However, the hydrogen evolution corrosion is the primary barrier to its widespread application. Herein, an imidazole-based ionic liquid, i.e., 1-(2-hydroxyethyl)-3-methylimidazolium chloride (HMIC), was examined as a corrosion inhibitor for Al-5052 alloy in 4 M NaOH electrolyte by electrochemical means, hydrogen evolution test and surface characterization. Electrochemical results showed that the inhibition efficiency was 58.2% when the concentration of HMIC was 7 mM, and the anode utilization increased to 82.9%. The findings of X-ray photoelectron spectroscopy (XPS) and molecular dynamics simulation demonstrated that HMIC can adsorb on the surface of Al-5052 to form a protective barrier and prevent the self-corrosion of Al anode. Moreover, the addition of HMIC significantly improved the discharge performance of the Al-air battery, with a nominal specific capacity (2469 mAh g−1) and energy density (3313 Wh kg−1). This electrolyte regulation strategy offers a way to enhance the Al-air battery's performance in alkaline medium. [Display omitted] • An ionic liquid (HMIC) was evaluated as a corrosion inhibitor for Al-air battery. • The addition of HMIC significantly increased the corrosion resistance of Al anode. • Surface characterization of Al-5052 alloy was examined by SEM, AFM, and XPS. • Energy density and anode utilization of the full battery were improved. • The inhibition mechanism of HMIC additive was elaborated. [ABSTRACT FROM AUTHOR]

Steel is an important material in industry. Adding heterocyclic organic compounds have proved to be very efficient for steel protection. There exists an empirical rule that the general trend in the inhibition efficiencies of molecules containing heteroatoms is such that O < N < S. However, an atomic-level insight into the inhibition mechanism is still lacked. Thus, in this work, density functional theory calculations was used to investigate the adsorption of three typical heterocyclic molecules, i.e. , pyrrole, furan, and thiophene, on Fe(110) surface. The approach is illustrated by carrying out geometric optimization of inhibitors on the stable and most exposed plane of α-Fe. Some salient features such as charge density difference, changes of work function, density of states were detailedly described. The present study is helpful to understand the afore-mentioned experiment rule. [ABSTRACT FROM AUTHOR]

• Corrosion inhibition of mild steel in 1 M HCl by N, S-CDs was investigated. • Inhibition efficiencies were experimentally achieved by EIS and PDP techniques. • Surface characterizations have been performed by SEM, AFM, and CAM tests. • The adsorption behavior was demonstrated by XPS. Novel N, S co-doped carbon dots (N, S-CDs) with memory effect were prepared by hydrothermal method using citric acid and l -cysteine as precursors. Structural and morphological characterizations confirmed that N, S-CDs are carbon dots with multifunctional groups and excellent water solubility. Electrochemical measurements indicated that N, S-CDs can effectively inhibit the charge transfer in the corrosion process of steel, and the inhibition efficiency is nearly 90%. The obtained N, S-CDs exhibits outstanding inhibition performance for steel corrosion, which offers a new thought for exploring environmentally friendly corrosion inhibitors. [ABSTRACT FROM AUTHOR]

• Surface morphology analysis provided that psidium guajava linn leaves extract exhibit excellent anti-corrosion ability. • Electrochemical test indicate psidium guajava linn leaves extract belong to the mixed-type inhibitor. • Psidium guajava linn leaves extract adsorb on the Cu surface in accordance with the Langmuir model. This work multi-angle explored the anti-corrosion nature and mechanism of psidium guajava linn leaves extract for copper in H 2 SO 4 environment.In this study, we used a simple and eco-friendly extraction way to acquire psidium guajava linn leaves extract (PGLLE). Fourier Transform infrared spectroscopy (FTIR) was executed to determine the active functional groups in PGLLE. Quantum chemical calculations effectively forecast the anti-corrosion characteristic of the four active substances in PGLLE. The results of molecular dynamics simulation predicted the stabilized adsorption configurations of the four substances in PGLLE on the Cu (1 1 1). Surface topography analysis can intuitively demonstrate that PGLLE effectually inhibits Cu corrosion. The data of electrochemical experiments show that the anti-corrosion capacity of PGLLE increases with the increase of the concentration in a certain interval. As the temperature hoists at definite temperature range, PGLLE can still be efficaciously adsorbed at the Cu surface, showing high-quality corrosion inhibition capabilities. Psidium guajava linn leaves can exist widely in nature, so it has great economic value as the inhibitor. Besides, PGLLE basically does not pollute the ecosystem when used as inhibitors. [ABSTRACT FROM AUTHOR]

In this work, we used experimental and theoretical calculation methods to investigate the corrosion inhibition nature of banana leaves water extract (BLWE) for X70 steel at 1 mol/L hydrochloric acid environment. The data of electrochemical tests manifest that the hydrochloric acid medium will accelerate the corrosion of X70 steel with increasing temperature. The charge transfer resistance dropped sharply from 55 Ω cm2 at 298 K to 18.4 Ω cm2 at 313 K. After adding BLWE in hydrochloric acid solution, the anti-corrosion efficiency of banana leaves extract for X70 steel can be maintained at about 90%. BLWE can simultaneously inhibit the anodic and cathodic reactions of X70 steel in hydrochloric acid solution, so it is mixed-type inhibitor. Surface morphology analysis strongly shows that BLWE can effectually restrain the corrosion of X70 steel. BLWE adsorption at the X70 steel surface is accord with Langmuir single-deck adsorption. Quantum chemical (QC) calculation and molecular dynamics simulations (MDS) have shown that (S)-2-amino-3-(4-hydroxyphenyl)propanoic acid (AHP), 3-(2-aminoethyl)-1H-indol-5-ol (ATI), and 3,4-Dihydroxycinnamic Acid (DDA) in BLWE can show excellent anti-corrosion character. QC calculation results show that AHP, ATI and DDA have small dipole moment values. The small dipole moment value is favorable the accumulation of inhibitor molecule on the X70 steel surface, thereby forming a denser barrier film. MDS results show that AHP, ATI and DDA can be adsorbed on the Fe (110) surface in parallel to obtain the maximum coverage. Unlabelled Image • Electrochemical test data indicate BLWE belong to the mixed-type corrosion inhibitor. • Surface characteristics analysis provided that BLWE exhibit excellent corrosion inhibition nature. • BLWE adsorb on the Fe/solution surface in accordance with the Langmuir model. [ABSTRACT FROM AUTHOR]

The corrosion inhibition performance of 5-Mercapto-1-phenyltetrazole (MPT) has been studied using theoretical calculation and abundant experimental methods. Electrochemical experiments show that MPT show high-efficiency corrosion inhibition ability for Q235 steel in H 2 SO 4 environment. The concentration of MPT is 5 mM, the anti-corrosion inhibition efficiency (η) is 98.1% at the 298 K. Besides, the anti-corrosion nature of MPT can keep about 98% in the temperature district of 298 K to 318 K. The test results of atomic force microscope (AFM) and scanning electron microscope (SEM) strongly prove that MPT can effectively adsorb at the Q235 steel interface, thereby effectively inhibiting the Q235 steel corrosion. The adsorption of MPT at the interface of Q235 steel conforms to Langmuir single-deck adsorption, and both physical and chemical adsorption exist. The theoretically calculated surface MPT has a large dipole moment and a small energy gap value, so it can exhibit high-quality corrosion inhibition performance. Unlabelled Image • Electrochemical data indicate MPT belong to the mixed-type inhibitor. • Surface characteristics analysis provided that MPT exhibit outstanding anti-corrosion nature. • MPT adsorb on the Q235 steel surface in accordance with the Langmuir model. • Theoretical calculation data show that MPT can exhibit good anti-corrosion performance. [ABSTRACT FROM AUTHOR]

In this work, we studied food flavor 2-Furfurylthio-3-methylpyrazine (FFM) as the green inhibitor for copper corrosion H 2 SO 4 solution. Electrochemical experiment data show that FFM can exhibit prominent anti-corrosion nature for copper in H 2 SO 4 medium in the temperature range of 298 K to 313 K. Potentiodynamic polarization curve results show that the corrosion inhibition efficiency of FFM can be as high as 97.9% at a concentration of 5 mmol/L. The surface morphology test results show that adding 5 mmol/L FFM in H 2 SO 4 medium, the copper sample is still relatively flat after soaking for 20 h, and the roughness values is only 7.84 nm. The XPS experimental results show that the S and N atoms in the FFM molecule can form N Cu and S Cu bonds on the copper surface to generate chemical adsorption. Besides, the FFM adsorption on the copper/solution surface conforms to the Langmuir monolayer adsorption model. The theoretical calculation results also prove that FFM can exhibit prominent anti-corrosion nature for copper in sulfuric acid medium. Unlabelled Image • Electrochemical test data indicates FFM belong to mixed-type corrosion inhibitor. • Surface topography results manifest that FFM exhibit excellent ant-corrosion nature. • Theoretical calculation results show that FFM can exhibit excellent corrosion inhibition performance. [ABSTRACT FROM AUTHOR]

Locust Bean Gum (LBG) was studied as a novel and eco-friendly corrosion inhibitor using experimental and theoretical calculation methods. These research methods include open-circuit potential (OCP), potentiodynamic polarization curves (PDP), electrochemical impedance spectroscopy (EIS), surface morphology analysis (AFM and SEM), quantum chemical calculations (QCC), and molecular dynamics simulations (MDS). Potentiodynamic polarization test data shows that when the concentration of LBG is 5 mM at 298 K, the corrosion inhibition efficiency of LBG is 89.8% for Q235 steel in 0.5 M H 2 SO 4 solution. AFM and SEM morphology maps convincingly confirm the data of electrochemical tests. The adsorption of LBG on Q235 steel/solution interface was consistent with Langmuir single-layer model. In addition, theoretical calculations show that LBG can show excellent corrosion inhibition performance. Unlabelled Image • Electrochemical test data indicates LBG is mixed-type corrosion inhibitor. • SEM and AFM data provided that LBG exhibit excellent anti-corrosion nature. • LBG adsorb onto the Fe surface in accordance with the Langmuir model. [ABSTRACT FROM AUTHOR]

An amino acid ionic liquid, namely 1-octyl-3-methylimidazolium L-prolinate ([OMIM]L-pro), was investigated as the corrosion inhibitor of copper in 3.5% NaCl solution through electrochemical techniques, surface analysis and molecular dynamics simulation. The results showed that [OMIM]L-pro was a mixed type inhibitor with a predominantly anodic action for copper in NaCl solution, its inhibition efficiency increased with the increase of concentration, but decreased with rising temperature, the highest inhibition efficiency was up to 97.5%. The adsorption of [OMIM]L-pro on the copper surface was found to follow the Langmuir isothermal equation, and the corrosion kinetic characteristics of copper in the test solution was discussed and analyzed. Moreover, L-prolinate anion was found to play a significant role in the corrosion inhibition performance of [OMIM]L-pro, but there was a synergistic effect between L-prolinate anion and imidazolium cation, which synergistically inhibited the corrosion of copper in NaCl solution. Molecular dynamics simulation data supported the experimental results. [ABSTRACT FROM AUTHOR]

In the present work, essential oil of Calamintha (EOC) was extracted from Calamintha plant and characterized by gas chromatography-mass spectrometry (GC-MS) and FTIR technique. In addition, EOC was evaluated as an ecological corrosion inhibitor of mild steel in 1 M HCl medium by various electrochemical techniques. Satisfactory consistency was obtained between the gravimetric method, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The maximum efficiency was recorded for the concentration of 1.5 g/L EOC which reached 87.57%. However, the morphology of the metal surface analyzed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) showed the appearance of a protective barrier on the steel surface. Finally, a theoretical study was carried out on the basis of the density functional theory (DFT) and molecular dynamics (MD) simulation technique. [ABSTRACT FROM AUTHOR]

In this work, high‐yield carbon quantum dots (CQDs) are successfully synthesized by a simple chemical oxidation method using acetaldehyde as raw material. Fourier‐transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetry (TGA), and XPS are used to analyze the structural characteristics of CQDs. The results demonstrate that many oxygen‐containing functional groups are on the surface of carbon nuclei. The inhibitive efficiency of electrochemical experiments and weight loss is 87.1 % and 95.3 %, respectively. SEM observes the surface morphology of the sample after 72 h corrosion with or without CQDs, and EDS analysis confirms that CQDs are effectively adsorbed on the surface of carbon steel. Furthermore, through calculation, the standard adsorption‐free energy of CQDs is −25 kJ/mol, concluding that the adsorption process is a combination of physisorption and chemisorption. This work is helping to solve the corrosion problem of metal equipment in the acid process. [ABSTRACT FROM AUTHOR]

Dalbergia odorifera leaves extract (DOLE) was obtained by soaking, filtering, and freeze-drying with 0.5 M H 2 SO 4 solution as solvent. The corrosion inhibition performance of X70 steel by DOLE was systematically studied by electrochemical research methods, surface morphology test, infrared spectrum test and theoretical calculation. The electrochemical test data show that the addition of DOLE in sulfuric acid medium can vastly reduce the electric double layer capacitance (C dl) value of the steel/acid interface, improve the charge transfer resistance, and simultaneously retard the cathodic and anodic reactions of X70 steel. The DOLE reaches 400 mg/L, the anti-corrosion efficiency (η) is 96 %. Fourier transform infrared spectroscopy (FTIR) test data show that DOLE contains a large number of hydroxyl groups, carbonyl groups and unsaturated functional groups, and a large number of lone electron pairs can coordinate with the empty d orbital of Fe, which leads to the formation of chemical adsorption of DOLE at X70 steel. The morphology test showed that the corrosion level of X70 steel decreased memorably after adding DOLE. The adsorption model study manifests that the adhere of DOLE at the interface of X70 steel comply with the Langmuir adsorption isotherm. Theoretical calculation demonstrate that DOLE can exhibit high-level inhibition property. [Display omitted] • Electrochemical test data indicate Dalbergia odorifera leaves extract belong to mixed-type corrosion inhibitors. • The Dalbergia odorifera leaves extract adsorb on the X70 steel surface in accordance with the Langmuir model. • Theoretical calculation provide in-depth understanding of the experimental results. [ABSTRACT FROM AUTHOR]

Sodium dodecyl benzene sulfonate (SDBS) was investigated as an eco-friendly inhibitor for zinc corrosion in 26% NH 4 Cl solution using corrosion experiments and theoretical calculations. Gravimetric and electrochemical results reveal that SDBS is an anodic inhibitor with excellent inhibition efficiency, which is further confirmed by field emission scanning electron microscope (FE-SEM) and atomic force microscopy (AFM) observation. The inhibitory effect diminishes with positive shift of potential, exhibiting a desirable characteristic for battery application. Despite the inhibition efficiencies decrease as increasing temperature from 298 to 328 K, the compound still shows favorable inhibitive ability at each temperature. In addition, the adsorption of SDBS on zinc surface obeys Langmuir adsorption model. Quantum chemical calculations and molecular dynamic simulations were further performed to correlate the adsorption mechanism with the structure of SDBS molecule. [ABSTRACT FROM AUTHOR]

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 0.5 M 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. [ABSTRACT FROM AUTHOR]

Due to environmental awarenesses and strict restrictions, industries are forced to bring their processes closer to the considered eco-friendly standards. Without a doubt, corrosion is the most obvious problem in industries and inhibitors are among the most applicable materials for metals' corrosion retardation. For this reason, extensive studies have been conducted in the field of green corrosion inhibitors in recent years. The present work concentrated on the evaluation of the bio-molecules from Mint leaves extract on the steel corrosion mitigation in HCl solution. The Mint extract (ME) structures were investigated by FTIR, UV-Vis, and Raman spectroscopies. It was shown by a polarization experiment that Mint extract at 800 ppm caused the current density (i corr) reduction from 1.03 mA/cm2 (for the blank sample) to 0.11 mA/cm2 which was aided by a mixed inhibition (cathodic – anodic) mechanism. The EIS results illustrated that at the optimum condition around 91 % inhibition degree was reached after introducing 800 ppm Mint extract. The weight loss investigations, however, affirmed that a 92 % efficiency was achievable at 25 °C, which was mitigated to 89 % at 55 °C. Eventually, the thermodynamic and adsorption isotherm records represented that Mint extract molecules mono-layer was constructed by utilizing the exothermic interactions. Via the MD and DFT simulations, the interfacial interactions and corrosion inhibitors' adsorption mechanism over the steel surface was exhibited. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to environmental awarenesses and strict restrictions, industries are forced to bring their processes closer to the considered eco-friendly standards. Without a doubt, corrosion is the most obvious problem in industries and inhibitors are among the most applicable materials for metals' corrosion retardation. For this reason, extensive studies have been conducted in the field of green corrosion inhibitors in recent years. The present work concentrated on the evaluation of the bio-molecules from Mint leaves extract on the steel corrosion mitigation in HCl solution. The Mint extract (ME) structures were investigated by FTIR, UV-Vis, and Raman spectroscopies. It was shown by a polarization experiment that Mint extract at 800 ppm caused the current density (i corr) reduction from 1.03 mA/cm2 (for the blank sample) to 0.11 mA/cm2 which was aided by a mixed inhibition (cathodic – anodic) mechanism. The EIS results illustrated that at the optimum condition around 91 % inhibition degree was reached after introducing 800 ppm Mint extract. The weight loss investigations, however, affirmed that a 92 % efficiency was achievable at 25 °C, which was mitigated to 89 % at 55 °C. Eventually, the thermodynamic and adsorption isotherm records represented that Mint extract molecules mono-layer was constructed by utilizing the exothermic interactions. Via the MD and DFT simulations, the interfacial interactions and corrosion inhibitors' adsorption mechanism over the steel surface was exhibited. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, researchers have tried to find potential approaches for mitigating the metals' corrosion rate in aggressive environments. In the present study, the exploration of the Pepper extract's impact on the steel samples (SS) dissolution rate reduction in HCl media was done. The extract ingredients were detected by Raman, UV-Vis, and FT-IR approaches. The Pepper extract mechanism and effectiveness in corrosion mitigation were examined by polarization approach and EIS exam. Adsorption of the inhibitive components in the Pepper extract over a steel surface was theoretically studied by DFT calculation and MD simulation. Around 92% efficiency with mixed protection activity was recorded after 6 h of sample exposure to the 800 ppm Pepper extract-included solution at ambient temperature. The FE-SEM and AFM records confirmed the considerable surface degradation reduction on the Pepper extract-containing HCl solution-attacked samples. The weight loss test results have reflected 91% efficiency at 800 ppm and ambient temperature. However, by raising the harsh media temperature up to 55 ºC the anti-corrosion index was reduced 90%. The thermodynamic computation proved the exothermic adsorption of the molecules according to the Langmuir-type isotherm proving the monolayer Pepper extract molecules' interaction with the iron surface. [Display omitted] • The Pepper extract's impact on the steel dissolution rate reduction in HCl media was studied. • Adsorption of the inhibitive components in Pepper extract over steel surface was theoretically studied. • Around 92% efficiency with mixed protection activity was recorded after 6 h sample exposure to the 800 ppm Pepper extract. [ABSTRACT FROM AUTHOR]

[Display omitted] 2,5-dihydroxy-1,4-dithiane (DDD) and 2,5-dimethy- [1.4] dithiane-2,5-diol (DTDD) two food flavors as environmentally-friendly inhibitors for Cu in 0.5 mol/L H 2 SO 4 media were researched via theoretical calculation and experimental ways. Electrochemical measurement data showed that DDD and DTDD can exhibit high level anti-corrosion feature. The anti-corrosion efficiency of DDD and DTDD were as high as 99.6% and 98.9%, respectively. The atomic force microscope (AFM) and scanning electron microscope (SEM) tests showed that the Cu specimens were immersed in the H 2 SO 4 with 5 mM DDD and DTDD for 30 h at the 298 K, and the Cu specimen surface was still smooth. Besides, the adsorption of DDD and DTDD at the interface of Cu/solution was comply with Langmuir adsorption. Theoretical calculation data showed that DDD exhibit more ascendant anti-corrosion feature than DTDD. [ABSTRACT FROM AUTHOR]

• The inhibition effectiveness of nitrogen-containing organics on copper was proved. • Triazole derivatives have better anti-corrosion performance at low concentration. • DFT and MD simulation provide support for the experimental results. Corrosion inhibitors are added to the slurry to mitigate the excessive corrosion of copper in the chemical mechanical polishing (CMP) process, and their adsorption mechanisms will affect the corresponding inhibition efficiencies. A comprehensive study of several types of inhibitors in the weak alkaline H 2 O 2 -sarcosine solution found that the number of heteroatoms and the substitution behavior of amino groups in nitrogen-containing organics could improve their corrosion inhibition efficiencies. The electrochemical results showed that all the inhibitors were mixed-type except for BIT, which was an anodic inhibitor. The benzo derivatives could not provide favorable inhibition at low concentrations, while the triazole derivatives are free from this deficiency. When 0.5 wt% inhibitors were added to the blank solution respectively, the corrosion inhibition performances of benzo derivatives ranked as IND < BZA < BIT, and the order of inhibition efficiencies of triazole derivatives is TAZ < 3-ATA < 5-ATZ. The SEM images of the polished wafer surfaces coincided with electrochemical experiments. Quantum chemical calculations predicted the reactive sites of molecules. Molecular dynamics simulations showed that triazole inhibitors could be adsorbed in parallel in the aqueous environment, while the benzo inhibitor molecules presented a certain tilt with the Cu (1 1 1) surface. [ABSTRACT FROM AUTHOR]

• • Electrochemical test data indicate Pyracantha fortuneana alcohol extracts belong to mixed-type corrosion inhibitor. • • The Pyracantha fortuneana alcohol extracts adsorb on the Cu in accordance with the Langmuir model. • • Theoretical calculation provide in-depth understanding of the experimental results. Compared with traditional copper corrosion inhibitors, Pyracantha fortuneana alcohol extracts are derived from natural plants, will not cause environmental pollution after use, and are in line with the concepts of green chemistry and sustainable development. In this study, Pyracantha fortuneana alcohol extracts (PFAE) were obtained by ethanol soaking extraction method. PFAE, a novel degradable green corrosion inhibitor, has been investigated by experiments and theoretical calculations for its anti-corrosion performance of copper in H 2 SO 4 solution. Electrochemical experiments have demonstrated a pronounced increase in corrosion inhibition efficiency (η) as the concentration of PFAE rises. At a PFAE concentration of 600 mg/L, the inhibition efficiency can exceed 95 %. Additionally, the electrochemical method was used to investigate how the effect of soaked time on its anti-corrosion performance. After 4 h of immersion in a H 2 SO 4 solution containing PFAE, the copper could still maintain more than 80 % of the anti-corrosion performance. The results of surface morphology analysis demonstrate that after adding PFAE, the roughness of the copper sample is significantly reduced. This provides intuitively evidence that PFAE can indeed proficiently inhibit copper corrosion within a sulfuric acid solution. According to the study of the adsorption model, it was found that the adsorption behavior of PFAE onto the copper surface adheres to the Langmuir monolayer adsorption model. Moreover, the findings indicate the coexistence of both physical and chemical adsorption mechanisms. The findings of molecular dynamics simulations (MD) and quantum chemistry (QC) calculations indicate that the six active components of PFAE can display strong anti-corrosion capability. [ABSTRACT FROM AUTHOR]

Solvothermal synthesis of functionalized carbon dots from amino acid as an eco-friendly corrosion inhibitor for copper in sulfuric acid solution. [Display omitted] In this work, novel N -doped carbon dots (N -CDs) were synthesized from citric acid and l -serine. The results of fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) show that there are many unsaturated bonds and polar groups in the N -CDs. The inhibition performance of the concerned zero-dimensional nanomaterial for copper was investigated by electrochemical, combining FT-IR, XPS and Raman to investigate the corrosion products. Results indicate that the N -CDs were found to be effective inhibitor with the suppression efficiency as high as 98.5% means after immersed for 24 h, and they interacted with copper substrate by chemical & physical adsorption. Moreover, the related anticorrosion mechanism was explored and elucidated in detail. The purpose of this work is to explore eco-friendly and efficient corrosion inhibitor materials for metal protection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Both DDA, DPD show excellent corrosion inhibition performance for cobalt. • Surface morphology of cobalt samples were examined by AFM and SEM. • The adsorption process of DDA, DPD follows Langmuir adsorption isotherm. • Experimental results were supported by DFT and molecular dynamics simulations. • The solubility and toxicity of DDA, DPD were evaluated by theory. Cobalt, as the barrier layer material for 14 nm copper interconnection, has been widely applied owing to its superior characteristics of low resistivity, excellent adhesion performance and blocking properties for copper. Most of the preciously developed cobalt corrosion inhibitors under weak alkaline condition are toxic, low water solubility, and limited to traditional experimental research. In this work, 3,3-dithiodipropionic acid (DDA), 2,2-dibenzamidodiphenyl disulfide (DPD) as potential corrosion inhibitors for cobalt in NH 4 Cl and H 2 O 2 media under alkaline environment were investigated. Electrochemical experiments, surface morphology characterization, quantum chemical calculation and molecular dynamic simulation were combined to analyze the corrosion inhibition ability and mechanism. The experimental and theoretical results present that these disulfide derivatives can inhibit the corrosion behavior of cobalt surface effectively in ammonium-based aqueous solutions. When the concentration of inhibitors was 0.5 wt%, the corrosion inhibition efficiency of DDA, DPD reach up to 92.9%, 91.41%, respectively. Their favorable capability is attributed to the dense adsorption films following the Langmuir adsorption isotherm. Besides, these two inhibitors show excellent performance of galvanic corrosion inhibition at the Co/Cu interface, which is consistent with the shift tendency simulations for binding to Co/Cu substrates. The results of water solubility and toxicity tests indicate that DDA is more suitable for industrial applications. [ABSTRACT FROM AUTHOR]

• The solubility and toxicity of PO were evaluated by theory. • PO shows excellent corrosion inhibition performance on Cu in EDTA-H 2 O 2 based system under alkaline condition. • The adsorption process of PO on Cu follows Langmuir adsorption isotherm. • Surface morphology of Cu surface was examined by SEM and AFM. • Experimental results were supported by DFT and molecular dynamics calculations. The application of corrosion inhibitors is one of the most effective methods developed to inhibit the corrosion of Cu interconnects. The performance of potassium oleate (PO) as a potential corrosion inhibitor for copper in EDTA-H 2 O 2 based solution was examined under alkaline environment. The inhibition efficiency and mechanism were studied by electrochemical characterization, surface morphology technology and molecular computing technology. Firstly, the water solubility and toxicity of PO were comprehensively evaluated. The results of electrochemical assessment manifest that the corrosion inhibition efficiency of PO for Cu can reach approximately 98.24%, even at relatively low concentration of PO (0.01 wt%), additionally, PO is a mixed-type corrosion inhibitor, which can effectively inhibit the corrosion circumstance of Cu in alkaline medium. These excellent performances are attributed to the physical and chemical properties of PO adsorption films formed by PO, which follows the Langmuir adsorption isotherm. Besides, Density Functional Theory (DFT) and molecular dynamics (MD) approaches were introduced to explore the most stable adsorption configuration and the most active adsorption sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • The inhibition efficiency of 99.34% was recorded for 700 ppm Zn + 300 ppm SHE. • A uniform organic/inorganic complex covered the steel surface. • The ratio of 300 ppm SHE + 700 ppm Zn showed the highest synergistic index (2.81) • A mixed protection behavior was observed according to the polarization test results. • The simulation results complemented the experimental findings. In this work, for the first time, the Satureja Hortensis leaves was extracted by ultra-pure water solution and then, the synergistic inhibition effect of various mixtures of Satureja Hortensis extract (SHE) and zinc cations on carbon steel corrosion in 3.5% saline (NaCl) solution was investigated. The proposed compounds' effectiveness in carbon steel corrosion mitigation was surveyed by polarization and EIS tests. The inhibition efficiency of 99.34% was recorded for 700 ppm Zn + 300 ppm SHE. Surface characterizations were conducted employing scanning electron microscope (SEM) equipped with EDX, ultraviolet–visible (UV–Vis) analysis, Fourier transmission infrared (FTIR) spectroscopy, grazing incidence X-ray diffraction (GIXRD), and contact angle (CA) analysis which vividly proved the results of the electrochemical investigation. A mixed protection behavior was observed according to the polarization test results. Molecular dynamics (MD) simulation results complemented the experimental findings in affording insights into the adsorption mechanism at the atomic/molecular scale. [ABSTRACT FROM AUTHOR]

The inhibitive effect and inhibition mechanism of l-lysine derivatives, namely α-N-benzyloxycarbonyl-l-lysine (α-NL) and ε-N-benzyloxycarbonyl-l-lysine (ε-NL), on the corrosion of carbon steel in 0.5 M H2SO4 solution were investigated by electrochemical technique, weightlessness test, scanning electron microscope, atomic force microscope, infrared attenuated reflectance spectroscopy and quantum chemical calculation. The results showed that α-NL and ε-NL as moderate cathodic inhibitors mainly inhibited the cathodic reaction of carbon steel in 0.5 M H2SO4 solution, and the terminal substituted ε-NL showed better corrosion inhibition than the α-N-benzyloxycarbonyl protected α-NL. Their inhibition efficiencies increased with the increase in inhibitor concentration, and the inhibition efficiency of α-NL and ε-NL with concentration of 10 mmol can reach 53.4% and 61.5%, respectively, but decreased with rising temperature. The adsorption of investigated inhibitors on the surface of carbon steel obeyed the modified Langmuir isotherm and El-Awady thermodynamic-kinetic model, and the thermodynamic and kinetic parameters were determined to discuss the mechanism of inhibition of α-NL and ε-NL. Moreover, Quantum chemical calculation gave further insight into the inhibition mechanism of α-NL and ε-NL and was employed to reveal the reasons for their differences in inhibition performance. [ABSTRACT FROM AUTHOR]

Diallyl disulfide (DAD), propyl disulfide (PPD) and dibenzyl disulfide (DBD) flavouring agents as copper corrosion inhibitors in 0.5 mol/L H 2 SO 4 solution were evaluated with multitudinous experiments including electrochemical techniques, morphological characterization measurements, FTIR spectra and theoretical calculations. The electrochemical results indicate that PPD and DBD show mixed-type inhibitors and DAD belongs to cathodic-type inhibitor, and the corrosion inhibition capacity follow order: PPD > DBD > DAD. The adsorption of these compounds on the surface of copper conforms to the Langmuir adsorption isotherm model. Furthermore, theoretical calculations were applied to deeply understand the inhibition mechanism of three disulfide-based compounds. [ABSTRACT FROM AUTHOR]

In this work, two indazole derivatives, namely 5-aminoindazole (AIA) and 5-nitroindazole (NIA), were investigated as corrosion inhibitors for carbon steel in 1 M HCl solution by experimental and density functional theory (DFT) methods. The electrochemical results indicate that the inhibition ability follows the order of AIA > NIA, which is due to the stronger electron-donating effect of –NH2 of the AIA group than the –NO2 group of NIA. Besides, the frontier orbital theory shows that the AIA exhibits higher reaction activity than NIA, and a more negative adsorption energy for AIA was also obtained, which is consistent with the analysis of the electrochemical measurements. We draw the conclusion that the electron-donating effect makes it easier for AIA to donate electrons to iron atoms to form a stronger protective layer than NIA. [ABSTRACT FROM AUTHOR]

[Display omitted] • The inhibition effect of traditional corrosion inhibitor BTA on cobalt pitting is not ideal. • The molecules of MBTA and TT-LYK have stronger electron donating ability than BTA. • The passivation films formed by MBTA and TT-LYK are more hydrophobic than BTA. • TT-LYK can protect cobalt from pitting in corrosive environmental. As integrated circuits shrink in feature size to 10 nm, the requirements of pitting defects on the cobalt (Co) surface become more stringent during the chemical mechanical polishing of Co interconnects. In this work, the corrosion inhibition effects of benzotriazole (BTA) and its two derivatives, 5-methyl benzotriazole (MBTA) and 2,2′-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bis-Ethanol (TT-LYK) in the slurry at pH 9 were studied by electrochemical methods, contact angle measurement, and scanning electron microscopy (SEM). The adsorption process of the three inhibitors on the cobalt surface could be described by the Langmuir isotherm model. All the azole corrosion inhibitors belong to anodic corrosion inhibitors for Co in a weak alkaline environment. When 8 mM BTA, MBTA and TT-LYK was added to the base solution containing 0.15 wt% glycine and 0.5 wt% H 2 O 2 , respectively, the corrosion inhibition efficiency reached 87.67%, 92.63% and 95.38%. In addition, the SEM results show that there are almost no pitting defects on the Co surface protected by TT-LYK. Furthermore, the quantum chemical parameters of the three inhibitors were calculated by molecular dynamics and density functional theory. The experimental data support the results of the density functional theory and Molecular dynamic simulation. [ABSTRACT FROM AUTHOR]

• Ranunculus bulbosus extract was used as a new environmentally-friendly corrosion inhibitor of MS exposed to 1 M HCl solution. • Using 2000 ppm Ranunculus bulbosus extract resulted in 94% corrosion inhibition efficiency according to EIS test results. • The inhibitor showed mixed inhibition and its adsorption obeyed a Langmuir isotherm. • Molecular simulations associated with DFT modeling highlighted the green ingredients adsorption on the steel. Owing to the movement toward greener earth, this study is a small contribution to this global process. The current research selected the Ranunculus bulbosus (RB) molecules in order to evaluate whether its extract could impart a corrosion-preventive quality to the MS attribute in the HCl condition. To reach this point, some distinct, as well as related tests, were performed. FESEM and AFM confirmed the positive impact of RB extract (RBE) upon the microstructure; the RBE addition considerably smoothened the surface in contrast with the sample doped with no RBE. UV–Vis showed the presence of several functional groups on the surface; while GIXRD provided the reason for the possible complexation of RBE molecules with Fe. Raman test confirmed the presence of inhibitor molecules on the surface via analyzing the carbon-based structures' existence. EIS was used for the corrosion-related analysis, and the increment of inhibitor concentration to 2000 ppm in company with 5 h of drowning time maximized the potency of corrosion resistance to 94%. Also, the corrosion-preventive performance of the RBE was supported by potentiodynamic polarization tests. RBE adsorbed over the surface via Langmuir regulation. Quantum chemical calculations based on the density functional theory (DFT) and molecular dynamics (MD) simulation have delivered helpful information regarding electron transfer and mechanism during adsorption of inhibitor ingredients on the mild steel surface. MD simulation revealed the interaction of inhibitors molecules and surface in addition to their high coverability. Also, DFT results suggested that electron sharing could occur between inhibitors molecules as metallic surfaces. In the end, the comparison of other studies with the current one was provided, and the mechanism was discussed. [ABSTRACT FROM AUTHOR]

A novelty ionic liquid 1-ethyl-2-benzyl bis (trifluoromethylsulfonyl) amides ([EBPz][NTf 2 ]) was synthesized and characterized. The corrosion protection of [EBPz][NTf 2 ] on AZ91D magnesium alloy in 0.05 wt% NaCl solution was studied. [Display omitted] • The ionic liquids [EBPz][NTf 2 ] is novelty and can protect AZ91D magnesium alloy well. • Under the influence of temperature, the inhibition efficiency of [EBPz][NTf 2 ] did not decrease obviously. • A combination of experimental and theoretical methods was used in the research. A novelty ionic liquid 2-benzyl-1-ethyl-1 H -pyrazolium bis (trifluoromethyl- sulfonyl) amides ([EBPz][NTf 2 ]) was synthesized and characterized, which is environmentally friendly and has high corrosion inhibition efficiency for AZ91D Mg alloy in 0.05 wt% NaCl solution. The corrosion properties of [EBPz][NTf 2 ] was studied by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDS), scanning electron microscope-energy dispersive spectrometer (SEM-EDX), atomic force microscope (AFM) and x-ray diffraction (XRD) analysis. The results show that the corrosion inhibition efficiency of [EBPz][NTf 2 ] reaches 91.4% when the concentration is 200 ppm..X-ray photoelectron spectroscopy (XPS) combined with the density functional theory (DFT) calculation was used to investigate the corrosion inhibition mechanism. [ABSTRACT FROM AUTHOR]

The corrosion of low–carbon steel in aggressive alkaline–saline environments is a very large problem. Protecting low–carbon steel from corrosion in aggressive alkaline–saline solutions using green inhibitors is a very important task in industry. However, there are no studies related to low–carbon steel corrosion in aggressive alkaline–saline environments. Green type corrosion inhibitors are an interesting topic of research. However, currently, the studied type inhibitors are not efficient at low concentrations, and there are no studies on them in aggressive alkaline–saline environments in regard to steel corrosion. In this research work, a novel gossypol–indole modification (GIM) is introduced as a green corrosion inhibitor for low–carbon steel in an aggressive alkaline–saline environment. This inhibitor is a large, highly planar structural molecule that is more water soluble than other inhibitors. Its inhibition behavior is stable at high temperatures, and it contains a large number of electron–rich heteroatoms. All of these properties make it an excellent corrosion inhibitor. The inhibition performance of the novel gossypol–indole modification for low–carbon steel in 1 M NaOH + 1 M NaCl is fully characterized by thermodynamic, gravimetric, electrochemical frequency modulation (EFM), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), density functional theory (DFT), molecular dynamics (MD) simulations, scanning electron microscopy (SEM) and energy dispersive X–ray spectrometry (EDX) methods. The results confirm that the novel gossypol–indole modification is an excellent inhibitor, with a maximum inhibition efficiency of 96.01% at 100 mg/L and 0.112 mM. The adsorption behavior follows the Langmuir isotherm. Electrochemical studies have indicated that this modified is a mixed–type corrosion inhibitor, and the theoretical investigations correlate well with the experimental results. [Display omitted] • Gossypol–indole modification is green and powerful corrosion inhibitor. • The maximum inhibition efficiency of GIM was 96.01% at 100 mg/L/0.112 mM. • GIM is mixed–type corrosion inhibitor. • Corrosion–cathodic and –anodic activities of low–carbon steel in aggressive alkaline–saline environment are significantly blocked with GIM. [ABSTRACT FROM AUTHOR]

• Carbon dots (CDs) are effective corrosion inhibitors for steel, copper and aluminium. • CDs inhibit corrosion of metals in acidic, saline and CO 2 -saturated saline solutions. • CDs counteract biocorrosion. • CDs protect metals against corrosion in sea water. The corrosion of metallic materials in aggressively acidic, saline, CO 2 -saturated saline and microbiological solutions is a continuous problem in the oil and gas industry. Using carbon dots (CDs) in corrosion protection is an ecological and environmentally efficient method because CDs have good water solubility, biocompatibility, low toxicity, excellent antibacterial properties, chemical stability, high thermal activity, and nonflammability. The inhibition performance of CDs was over 95–99% at low concentrations and medium temperatures. The CDs contain more pyrrole-like N, pyridine-N, graphitic N atoms and O atoms, in which the lone electron pairs promote CDs to become efficient corrosion inhibitors. The CDs formed rigid covalent bonds with the metal surface through π-electrons transfer. The CDs easily substituted with the pre-adsorbed water on the metal surface. In this review, the inhibition, adsorption, electrochemistry, surface morphology and structural characteristics of CDs for steel, copper and aluminium in aggressively acidic, saline, CO 2 -saturated saline and microbiological solutions are reviewed and discussed. [ABSTRACT FROM AUTHOR]

• GCU is introduced as a green corrosion inhibitor. • Maximum inhibition efficiency of GCU is 95.62% at 100 mg/L/0.08 mM. • GCU is a mixed-type corrosion inhibitor. • Bond length of Fe-O is approximately 2.4 Å. • Adsorption energy of GCU on Fe(1 0 1) surface is − 390.1 kcal/mol. The corrosion of St3 steel in 1 M NaCl saturated with CO 2 and H 2 S is a large problem in the chemical industry; therefore, creating green and more efficient inhibitors is an urgent task. However, there have been extremely limited research results related to this problem. In this research, a novel glycoluril pharmaceutically active compound (GCU) was first introduced as a green corrosion inhibitor for St3 steel in 1 M NaCl saturated with CO 2 and H 2 S. The inhibition properties of the novel glycoluril pharmaceutically active compound were fully characterized by thermodynamic, gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), linear polarization resistance (LPR), density functional theory (DFT), molecular dynamics (MD) simulation, scanning electron microscopy (SEM) and energy dispersive X–ray spectrometry (EDX) methods. The obtained results indicated that this inhibitor is an excellent inhibitory molecule, and its maximum protection degree was 95.62% at 100 mg/L/0.08 mM. The adsorption behaviour of this inhibitor was characterized from a Langmuir isotherm. Electrochemical studies demonstrated that this molecule is a mixed–type corrosion inhibitor. The theoretical calculations indicated a good correlation with the experimental results and confirmed that the adsorption–inhibition character depends on the molecular structure of the inhibitor and that the protonated form of the inhibitor is more inhibited than its neutral form. [ABSTRACT FROM AUTHOR]

• The EIS has confirmed, that at 100 mg/L extract shows inhibition efficiency > 95%. • At LCS surface adsorption of extract has been confirmed by SEM and AFM techniques. • The adsorption behavior of main phytochemicals has been explained by DFT and MD. The soxhlet extraction method was used to prepare the extract of Cinnamoum tamala (C. tamala). Corrosion resistance performance of C. tamala leaves extract for low carbon steel (LCS) in the solution of 0.5 M H 2 SO4 was examined by Eletrochemical impedance spectroscopy (EIS), Tafel and gravimetric loss studies. Notably, C. tamala showed much high 96.76% industrial required efficiency at very low 100 mg/L critical concentration. Theoretical studies, using UV–vis, Density functional theory (DFT) and molecular dynamics (MD) simulation, were led as a valuable report for understanding the electronic adsorption, comparative inhibitory activities of phytochemicals. The results obtained revealed that C. tamala extract might be used as a highly efficient industrial required corrosion inhibitor. [ABSTRACT FROM AUTHOR]

The corrosion of steel materials in alkaline-saline media is the largest problem in industry. Economical and environmentally friendly corrosion inhibitors are crucial for corrosion protection. The present work is the first to introduce a novel cucurbit[6]uril-based [3]rotaxane supramolecular ionic liquid (CB6-based [3]rotaxane) as a green and efficient corrosion inhibitor for the chemical industry. The correlation between the supramolecular ionic liquid system and inhibition behavior was studied first. The inhibition characteristics of CB6-based [3]rotaxane in 1 M OH– + 1 M Cl– solution were first fully investigated by thermodynamic, gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), electrochemical noise (EN), cyclic voltammetry (CV), density functional theory (DFT), molecular dynamics (MD) simulation, scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) methods. The experimental results confirmed that CB6-based [3]rotaxane exhibited excellent corrosion resistance, and its inhibition efficiency was 97.97% at 100 mg/L and 0.032 mM. The electrochemical results suggested that (i) CB6-based [3]rotaxane was a mixed-type corrosion inhibitor with anodic dominance; (ii) the supramolecular part of selected ionic liquid is responsible for notably blocks the charge transfer process on the metal surface. The theoretical findings correlated well with the experimental results and revealed that the protonated form of this supramolecular structure exhibited better performance than its neutral form. MD simulations results suggested that the bond length of the Fe(surface)-inhibitor (3.127 Å) is less than 3.5 Å, which indicates that chemisorption is dominant in the investigated adsorption system. Molecular electrostatic potential analysis confirmed that the studied ionic liquid-supramolecular system contained most favorable nucleophilic centers, which are responsible for excellent inhibition performance. [Display omitted] • A novel cucurbit[6]uril-based [3]rotaxane (CU6R) was introduced for the first as a green and efficient corrosion inhibitor for the chemical industry. • Carbon steel inhibition in an aggressive alkaline-saline solution was studied with a CU6R for the first time. • The inhibition characteristics of CU6R in 1 M OH– + 1 M Cl– solution were fully studied. • The MD simulation findings that CU6R interacts well with the Fe(101) surface. [ABSTRACT FROM AUTHOR]

The corrosion of steel materials in alkaline-saline media is the largest problem in industry. Economical and environmentally friendly corrosion inhibitors are crucial for corrosion protection. The present work is the first to introduce a novel cucurbit[6]uril-based [3]rotaxane supramolecular ionic liquid (CB6-based [3]rotaxane) as a green and efficient corrosion inhibitor for the chemical industry. The correlation between the supramolecular ionic liquid system and inhibition behavior was studied first. The inhibition characteristics of CB6-based [3]rotaxane in 1 M OH– + 1 M Cl– solution were first fully investigated by thermodynamic, gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), electrochemical noise (EN), cyclic voltammetry (CV), density functional theory (DFT), molecular dynamics (MD) simulation, scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) methods. The experimental results confirmed that CB6-based [3]rotaxane exhibited excellent corrosion resistance, and its inhibition efficiency was 97.97% at 100 mg/L and 0.032 mM. The electrochemical results suggested that (i) CB6-based [3]rotaxane was a mixed-type corrosion inhibitor with anodic dominance; (ii) the supramolecular part of selected ionic liquid is responsible for notably blocks the charge transfer process on the metal surface. The theoretical findings correlated well with the experimental results and revealed that the protonated form of this supramolecular structure exhibited better performance than its neutral form. MD simulations results suggested that the bond length of the Fe(surface)-inhibitor (3.127 Å) is less than 3.5 Å, which indicates that chemisorption is dominant in the investigated adsorption system. Molecular electrostatic potential analysis confirmed that the studied ionic liquid-supramolecular system contained most favorable nucleophilic centers, which are responsible for excellent inhibition performance. [Display omitted] • A novel cucurbit[6]uril-based [3]rotaxane (CU6R) was introduced for the first as a green and efficient corrosion inhibitor for the chemical industry. • Carbon steel inhibition in an aggressive alkaline-saline solution was studied with a CU6R for the first time. • The inhibition characteristics of CU6R in 1 M OH– + 1 M Cl– solution were fully studied. • The MD simulation findings that CU6R interacts well with the Fe(101) surface. [ABSTRACT FROM AUTHOR]

• A novel bromide–cucurbit[7]uril (BrCU) supramolecular ionic liquid was first introduced as a green corrosion inhibitor. • The maximum inhibition efficiency of BrCU was 97.54% at 100 mg/L/0.06 mM. • The obtained PDP data suggested that BrCU was a predominantly anodic mixed–type corrosion inhibitor. • Theoretical calculations support the experimental results. Metal corrosion is the largest problem in the oil and gas industry. Therefore, providing metallic materials with corrosion protection is an urgent task in modern research. The use of green corrosion inhibitors for corrosion protection is very important both ecologically and economically. This work is the first to introduce a novel bromide–cucurbit[7]uril (BrCU) supramolecular ionic liquid as an excellent corrosion inhibitor for the oil and gas industry. Its inhibition behaviour for carbon steel in 1 M NaCl saturated with CO 2 and H 2 S was first fully identified through the use of thermodynamic and gravimetric analysis, electrochemical noise (EN), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), density functional theory (DFT), scanning electron microscopy (SEM) and energy dispersive X–ray spectroscopy (EDX) methods. The experimental results confirmed that BrCU is an excellent environmentally friendly corrosion inhibitor for the gas and oil industry. Its inhibition efficiency was 97.54% at 100 mg/L/0.06 mM, and it was more stable at high temperature (333 K). A Langmuir isotherm was applied to identify the adsorption character of BrCU on the metal surface. The obtained PDP data suggested that BrCU was a predominantly anodic mixed–type corrosion inhibitor. Theoretical calculations showed good correlation with the experimental results, indicating that the halogen modification in the supramolecular ionic liquid system improved the inhibition performance. [ABSTRACT FROM AUTHOR]

• Corrosion inhibition of mild steel in 0.5 mol/L H 2 SO 4 by different solvent fractions of bamboo shoots extract were investigated. • Inhibition efficiencies were experimentally achieved by electrochemical and weight loss techniques. • Surface characterizations have been performed by SEM and XPS tests. • Experimental results have been combined by theoretical studies (DFT and MD). The ethanol extract of bamboo shoots was obtained by refluxing bamboo shoots in 95 % ethanol, and then the ethanol extract from bamboo shoots were separated by organic solvents with different polarity, including petroleum ether, dichloromethane, ethyl acetate and n-butanol. The inhibitive effect of different solvent extraction fractions of bamboo shoot extract on the corrosion of mild steel in 0.5 mol/L H 2 SO 4 solution was investigated through electrochemical technique, weight loss test, scanning electron microscope and X-ray photoelectron spectroscopy. Electrochemical results showed that all extraction fractions of bamboo shoots extract, as modest cathodic inhibitors, mainly inhibited the cathodic reaction of mild steel in 0.5 mol/L H 2 SO 4 solution, and the inhibition efficiency of extraction fraction increased with the increase in its concentration. When the concentration was 0.4 g/L, the corrosion inhibition efficiency of dichloromethane fraction (DCMF), n-butanol fraction (nBF), ethyl acetate fraction (EAF) and the residual fraction (RF) are 93.03%, 89.62%, 85.33% and 64.84%, respectively. However, the results of weight loss experiment showed that when the experimental time increased from 4 h to 24 h, the inhibition efficiency of DCMF and EAF decreased significantly, but that of nBF remained at about 86%, showing a better long-term effect. Surface analysis technology was used to investigate the corrosion inhibition and adsorption behavior of the extraction extraction fractions, and the adsorption of different solvent extraction fractions of bamboo shoot ethanol extract on mild steel surface was in accordance with the equation of Langmuir isotherm. [ABSTRACT FROM AUTHOR]

[Display omitted] • TODTI was investigated as a green and effective corrosion inhibitor. • TODTI inhibitor indicated a high efficiency of 96.72% at 200 mg/L. • The inhibitor adsorbs on steel surface following Langmuir isotherm. • PDP results confirmed that TODTI is a mixed type of inhibitor with anodic dominance. • Theoretical investigations suggested the better performance of the protonated form of inhibitor. The new and eco–friendly corrosion inhibitor based on thioglycoluril derivative (2–thioxo–5,5–di–p–tolylimidazolidin–4–one (TODTI)) for St2 steel in 1 M HCl + 1 M Na 2 SO 4 solution was first introduced and its inhibition properties were first fully characterised by gravimetric, thermodynamic, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), electrochemical noise (EN), electrochemical frequency modulation (EFM), density functional theory (DFT), molecular dynamics (MD) simulations, scanning electron microscopy (SEM) and energy dispersive X–ray spectrometry (EDX) methods. The effect of thioglycoluril rings on the St2 steel inhibition and salt–corrosion on the St2 steel surface was first studied. The experimental results indicated that TODTI had excellent inhibition abilities (96.72% at 200 mg/L/0.675 mM) at medium temperatures (303–333 K); the St2 steel was maximally inhibited and salt–corrosion was importantly reduced with the adsorption of thioglycoluril rings on the metal surface in the aggressive hydrochloric acid with sulfate ions. The electrochemical investigations revealed that TODTI is a mixed–type corrosion inhibitor, and its adsorption nature was confirmed according to the Langmuir isotherm. The quantum chemical calculations confirmed a good correlation with the experimental results and indicated that the inhibitory nature of TODTI is linked to its quantum chemical characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Environmentally adaptable ionic liquids protect Mg alloys in different environments. • The corrosion effect has good persistance and it can last for 7 days. • The ionic liquids can spontaneously form a dense film on the surface of Mg alloys. • The inhibition mechanism is studied by experiment and theoretical calculation. The influence of pyrazolium ionic liquid 1- n -butyl-2-decylpyrazole bistrifluoromethanesulfonimide ([BDePz][NTf 2 ]) on the corrosion behavior of AZ91D magnesium alloys in NaCl solution with three different concentrations and ASTM D1384-87 corrosive solution was explored by electrochemical measurements and SEM, AFM. Results revealed that as the concentration of Cl− increases, the corrosion inhibition performance of magnesium alloy inhibitor is slightly lower, but still good. The maximum corrosion inhibition efficiency is 90.4% in 0.05 wt% NaCl and 82.0% in ASTM D1384-87 corrosive solution. After soaking in the inhibitor-ethanol solution, the surface of the magnesium alloy is still relatively smooth after soaking in the four corrosion solutions for 7 d. The possible inhibition mechanism is proposed according to the XPS and XRD results as well as the molecular dynamics simulations and quantum chemical calculations. [ABSTRACT FROM AUTHOR]

• Thioglycoluril was introduced as a new and green corrosion inhibitor for low carbon steel in aggressive acidic media. • The inhibition efficiency of BSTGCU was over 96% at 100 mg/L. • Electrochemical measurements suggested that BSTGCU is a mixed-type inhibitor. • Theoretical results confirmed that the inhibition performance of BSTGCU was better in its protonated form than in its neutral form in the aqueous phase. Thioglycoluril (3a,6a−bistolylthioglycoluril (BSTGCU)) was first introduced as a new and green corrosion inhibitor for low carbon steel in a 1 M HCl medium. The inhibition properties of BSTGCU in a 1 M HCl were fully characterised by the gravimetric, thermodynamic, potentiodynamic polarisation (PDP), electrochemical impedance spectroscopy (EIS), electrochemical noise (EN), electrochemical frequency modulation (EFM), density functional theory (DFT), molecular dynamics (MD) simulations, scanning electron microscopy (SEM) and energy dispersive X −ray spectrometry (EDX) methods. The experimental results confirmed that the maximum inhibition efficiency of BSTGCU was over 96% at 100 mg/L in a 1 M HCl medium. The electrochemical results indicated that BSTGCU acted as a mixed−type inhibitor and spontaneously adsorbed on the metal surface by physical and chemical adsorption mechanisms according to its Langmuir adsorption isotherms. The SEM−EDX results of the inhibited steel sample revealed that the surface morphology was significantly improved with the presence of inhibitor. Theoretical calculations confirmed that the inhibition properties depended on the molecular structure of BSTGCU, and its inhibition performance was better in its protonated form than in its neutral form in the aqueous phase. [ABSTRACT FROM AUTHOR]

The inhibition properties of 4,5-dihydroxy-4,5-di-p-tolylimidazolidine-2-thione (DHDTIT) for use on carbon steel in a 1 M NaOH +1 M NaCl medium was fully characterised and investigated by thermodynamic, electrochemical, surface and theoretical analyses. The obtained results are as follows. The inhibition efficiency of DHDTIT for carbon steel is over 95–96% at the optimum concentration in this medium. DHDTIT demonstrates mixed-type behaviour. The negative values of ∆G ads o and ∆H ads o show that the inhibition process occurs spontaneously and that the physical and chemical adsorption on the metal surface is endothermic. The C dl and solution conductivity are very low in the inhibited medium. DFT calculations confirm the experimental results and indicate that the molecular structure is a significant factor of the inhibition characteristics. Finally, molecular dynamics (MD) simulations confirm the successful interfacial adsorption of this inhibitor on the Fe (110) surface. Unlabelled Image • DHDTIT is excellent corrosive inhibitor for carbon steel in 1 M NaOH +1 M NaCl medium. • Inhibition efficiency of DHDTIT is 96% at 100 mg/L. • DHDTIT is mixed type corrosive inhibitor. • Inhibition efficiency of DHDTIT depends on its molecular structure. [ABSTRACT FROM AUTHOR]

• ACDs exhibited good efficiency in acidic solution. • Simulations showed excellent correlation with experimental data. • EFM showed potential mitigation of steel by ACDs at 600 mg/L. • SEM and AFM confirmed inhibitor/metal complex formation. Two new acridinedione namely 3,3,6,6-Tetramethyl-9,10-diphenyl-3,4,6,7,9,10-hexahydro-1,8-(2H,5H)-acridinedione (ACD-1), and 9-(4-methoxyphenyl)-3,3,6,6-tetramethyl-10-phenyl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione (ACD-2) were synthesized and tested as prominent inhibitors for N80 steel corrosion inhibition in 15% hydrochloric acid (HCl). The weight loss result showed maximum efficiency of 97.3% (ACD-2) and Langmuir isotherm model best explained the adsorption of ACDs. EIS study reveals R ct value increased to a maximum of 816.4 Ωcm2 with the inhibition efficiency of 95.6% at 600 mg/L (ACD-2). The results of PDP proposed that ACDs are mixed but cathodic dominance inhibitors. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) tests supports the adsorption of ACDs molecules onto the N80 steel surface. Intermolecular interactions and dynamics were studied using density functional theory (DFT) and molecular dynamics (MD). [ABSTRACT FROM AUTHOR]

Losartan Potassium (LP) is a commonly used drug for the treatment of hypertension. In this study, the corrosion inhibition performance of LP on copper in 0.5 M H 2 SO 4 was investigated using electrochemical methods, surface morphological observation, X-ray photoelectron spectroscopy (XPS), quantum chemical calculation and molecular dynamics (MD) simulation. The electrochemical results show that LP is a type of mixed-type inhibitor that suppresses both cathode and anode reactions by forming a protective film. This film follows the Langmuir adsorption model and mainly depends on chemisorption in this process. XPS analysis confirmed that the adsorption film was due to the formation of coordination compounds between N atoms in the LP molecule and copper. Quantum chemical calculation further confirmed the active centres of N atoms in LP molecules, and MD simulation demonstrated that the inhibitor was adsorbed almost tightly and parallel to the Cu (111) surface. • An eco-friendly drug LP was used as corrosion inhibitor for copper. • LP has good anti-corrosion effect with the highest efficiency of 94.9%. • XPS analysis shows LP is adsorbed on copper by a N:Cu (400.79 eV) bond. • Theory calculations demonstrate the adsorption mechanism of LP on copper. [ABSTRACT FROM AUTHOR]

2,2′-Dithiosalicylic acid (DSA), 2-aminophenyl disulfide (APD) and 2,2-dibenzamidodiphenyl disulfide (DPD) were determined for corrosion inhibition of Cu in H 2 SO 4 media by electrochemical tests, surface morphology analysis, quantum chemical calculations and molecular dynamics simulations. The results of polarization curves showed that DSA, APD and DPD reveal good anti-corrosion capacity. They can simultaneously inhibit the cathodic and anodic reactions of copper. Therefore, they belong to the mixed-type corrosion inhibitors. Impedance spectroscopy results showed that when DSA, APD and DPD adsorption on the surface of Cu, the charge transfer resistance increases significantly and typical capacitance behavior produced, which indicates that the formed inhibitor film is very dense and ordered. In addition, the adsorption of corrosion inhibitors on the Cu surface is conforming to Langmuir monolayer adsorption. The experimental results obtained by surface topography analysis are consistent with the results of electrochemical experiments. Their corrosion inhibition ability is DSA < APD < DPD. Theoretical calculations further explore the relationship between corrosion inhibition performance and their molecular configurations. • Electrochemical test data indicates that the inhibition efficiency is DSA < APD < DPD. • The DSA, APD, and DPD adsorb on the Cu surface in accordance with the Langmuir model. • Quantum chemistry research and molecular dynamics simulation provide in-depth understanding of the experimental results. [ABSTRACT FROM AUTHOR]