Novel porphyrin derivatives as corrosion inhibitors for stainless steel 304 in acidic environment: synthesis, electrochemical and quantum calculation studies

Eco-friendly impact of a novel green Melilotus officinalis extract as a sustainable inhibitor to reduce acid corrosion of copper

In this study, we deployed green Melilotus officinalis extract (MOE) as a corrosion inhibitor for copper. The anticorrosion properties of MOE for Cu in 1 M HNO3 were investigated by various experimental and numerical techniques, including potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and a weight loss (WL) method at different temperatures. Additionally, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray analysis (EDX) and atomic force microscopy (AFM) were utilized to examine the surface morphology of Cu with and without the extract. By contrasting the inhibition effectiveness with and without the extract, the inhibition efficiency (% IE) was observed. The WL method revealed that 300 ppm of the extract had an IE of 93.8% for Cu immersed in one molar HNO3 solution. The MOE was classified as a mixed type according to the PDP study since it delayed both cathodic and anodic processes, with a cathodic predominance. At 25-45 °C, MOE's free adsorption energies were 23.1-21.5 kJ mol-1, showing that mixed-type adsorption occurred on the Cu surface. Additionally, the Langmuir adsorption isotherm and the adsorption data from the WL tests of MOE showed a good match. The extract could adsorb spontaneously onto the metal surface, according to the thermodynamic conditions. Analysis of the corrosion product using different techniques revealed that a protective layer had formed on the metal's surface. Hence, MOE had a good corrosive inhibitive effect on Cu in HNO3 solution. It turned out that all the methods used gave consistent results.

Exploring the Experimental and Theoretical Studies and Inhibition Mechanism of Passiflora Incarnata Extract as a Novel Green Inhibitor for API 5CT N80 in an Aggressive Environment

Corrosion is a crucial problem worldwide that heavily affects natural and industrial environments and can cause machinery breakdown and deterioration of construction assemblies, thus threatening the lives of humans and accelerating the consumption of natural metal reservoirs. In this study, we deployed passiflora incarnata extract (PIE) as an eco-friendly green inhibitor to prevent API 5CT N80 (CS-N80) corrosion in 1 M HCl. The chromatograms of the gas chromatography-mass spectroscopy analysis of PIE have identified 25 compounds. The weight loss method reveals that 150 ppm of the extract offers 90.4% inhibition efficiency (IE) to CS-N80 immersed in 1 M HCl solution at 25 °C. However, at higher temperatures (45 °C), % IE increases and reaches 92.1%. The electrochemical characterization of the adsorbed layer on CS-N80 was tested by utilizing electrochemical methods (electrochemical impedance spectroscopy and polarization) in 1 M HCl. Polarization diagrams displayed that PIE is a mixed-type inhibitor that retards CS-N80 corrosion. Temkin adsorption isotherm is the best fit for adsorbed PIE on the CS-N80 surface. IE was improved by raising the temperature (chemical adsorption). Examining the morphology of CS-N80 sheets through scanning electron microscopy, energy-dispersive X-ray, X-ray photoelectron spectroscopy, and Fourier transform infrared analysis furnishes valuable insights into their surface characteristics. The results of a quantum chemical computation show that the three PIE components have strong anticorrosion properties. According to findings from molecular dynamics simulations, the three PIE components can have a high binding energy and can be adsorbed in a parallel manner at the Fe(110) surface. All tests have shown that the PIE composite conversion adsorbed with a self-healing property and lower corrosion current density was precipitated on the steel surface.

Synthesis of new binary trimethoxyphenylfuran pyrimidinones as proficient and sustainable corrosion inhibitors for carbon steel in acidic medium: experimental, surface morphology analysis, and theoretical studies

In this study, synthesis and assessment of the corrosion inhibition of four new binary heterocyclic pyrimidinones on CS in 1.0 M hydrochloric acid solutions at various temperatures (30-50 °C) were investigated. The synthesized molecules were designed and synthesized through Suzuki coupling reaction, the products were identified as 5-((5-(3,4,5-trimethoxyphenyl)furan-2-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (HM-1221), 2-thioxo-5-((5-(3,4,5-trimethoxyphenyl)furan-2-yl)methylene)dihydropyrimidine-4,6(1H,5H)-dione (HM-1222), 1,3-diethyl-2-thioxo-5-((5-(3,4,5-trimethoxyphenyl)furan-2-yl)methylene)dihydropyrimidine-4,6(1H,5H)-dione (HM-1223) and 1,3-dimethyl-5-((5-(3,4,5-trimethoxyphenyl)furan-2-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (HM-1224). The experiments include weight loss measurements (WL), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). From the measurements, it can be shown that the inhibition efficiency (η) of these organic derivatives increases with increasing the doses of inhibitors. The highest η recorded from EIS technique were 89.3%, 90.0%, 92.9% and 89.7% at a concentration of 11 × 10-6 M and 298 K for HM-1221, HM-1222, HM-1223, and HM-1224, respectively. The adsorption of the considered derivatives fit to the Langmuir adsorption isotherm. Since the ΔGoads values were found to be between - 20.1 and - 26.1 kJ mol-1, the analyzed isotherm plots demonstrated that the adsorption process for these derivatives on CS surface is a mixed-type inhibitors. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM) and Fourier- transform infrared spectroscopy (FTIR) were utilized to study the surface morphology, whereby, quantum chemical analysis can support the mechanism of inhibition. DFT data and experimental findings were found in consistent agreement.

Eco-Friendly Piper cubeba Official Extract Corrosion Inhibition of C-Steel in 1 M Sulfamic Acid

This work offers a high-performing, environmentally friendly corrosion inhibitor for carbon steel in 1 M sulfamic acid (H2NSO3H). Potentiodynamic polarization and electrochemical impedance spectroscopy were used to evaluate the anticorrosion properties of Pipper cubeba official extract (P.cubebaOE) for carbon steel in 1 M H2NSO3H at 25 to 45 °C. At a temperature of 45 °C, the P.cubebaOE reached a maximum corrosion inhibition efficiency of 96%. P.cubebaOE was also subjected to Fourier transform infrared spectroscopy in order to ascertain its primary chemical composition. Additionally, the behavior of P.cubebaOE in terms of corrosion inhibition on carbon steel was examined at the microscopic level using scanning electron microscopy. The findings demonstrate that P.cubebaOE's adsorption type on carbon steel conforms to the Langmuir adsorption isotherm model. Based on the adsorption isotherm model, the free energy was estimated to be approximately -20.0 kJ/mol, suggesting that P.cubebaOE is physically adsorbing on the surface of carbon steel. The results of the density functional theory and molecular dynamics simulations show that P.cubebaOE exhibits excellent inhibition performance on carbon steel in H2NSO3H solution and are consistent with the electrochemical experimental results. This work offers significant information on the development of environmentally friendly corrosion inhibitors for carbon steel.

The impact of environmentally friendly supramolecular coordination polymers as carbon steel corrosion inhibitors in HCl solution: synthesis and characterization

Two 3D-supramolecular coordination polymers (SCP1 & SCP2) have been synthesized and characterized by physicochemical and spectroscopic methods. In a solution of 1.0 M HCl, SCPs were used to prevent corrosion of carbon steel (CS). The inhibition productivity (%η) rises as the synthetic inhibitor dose rises, and the opposite is true as the temperature rises. The study was carried out using chemical (mass loss, ML) and electrochemical ( potentiodynamic polarization, PDP and electrochemical impedance microscopy, EIS) techniques, which showed %η reached to 93.1% and 92.5% for SCP1 & SCP2, respectively at 21 × 10-6 M, 25 °C. For the polarization results, SCPs behave as mixed-type inhibitors. With increasing doses of SCPs, the charge transfer resistance grew and the double layer's capacitance lowered. The creation of a monolayer on the surface of CS was demonstrated by the finding that the adsorption of SCPs on its surface followed the Henry adsorption isotherm. The parameters of thermodynamics were computed and explained. The physical adsorption of SCPs on the surface of CS is shown by the lowering values of free energy (∆Goads < - 20 kJ mol-1) and increasing the activation energy (E*a) values in presence of SCP1 & SCP2 than in their absence. Atomic force microscope (AFM) and scanning electron microscopy (SEM) demonstrated the development of a protective thin film of SCPs precipitated on the surface of CS. There is a strong matching between results obtained from experimental and theoretical studies. Results from each approach that was used were consistent.

Insights into the use of two novel supramolecular compounds as corrosion inhibitors for stainless steel in a chloride environment: experimental as well as theoretical investigation

Novel supramolecular (SCPs) compounds such as: {[Ni (EIN)4(NCS)2]}, SCP1 and {[Co (EIN)4 (NCS)2]}, SCP2 have been studied using weight loss (WL) and electrochemical tests on the corrosion performance of stainless steel 304 (SS304) in 1.0 M hydrochloric acid (HCl) solution. The experimental results revealed that inhibition efficacy (η%) rises with increasing concentrations of SCPs and reached 92.3% and 89.6% at 16 × 10-6 M, 25 °C, from the WL method for SCP1 and SCP2, respectively. However, by raising the temperature, η% was reduced. Polarization measurements (PDP) showed that the SCPs molecules represent a mixed-type. The SCPs were adsorbed on a SS304 surface physically, and the Langmuir adsorption isotherm was found to govern the adsorption process. The determination of thermodynamic parameters was carried out at various temperatures. Quantum chemical calculations were calculated to prove the adsorption process of SCP components, using the molecular dynamics (MD) simulations and electron density map. The inhibition performance of SCPs for SS304 dissolution in an acidic medium was proved to be excellent through FT-IR and AFM analysis. The results obtained from all measurements exhibit a high level of agreement with each other.