The present work, novel growth of ternary CuO-Fe3O4/g-C3N4 nanocomposites (NCs) with three different ratio (CuO-Fe3O4:g-C3N4 = 90:10; 75:25 and 50:50), binary CuO-Fe3O4 nanocomposite (NC) and its ...pristine g-C3N4, CuO and Fe3O4 was synthesized and characterized by XRD, SEM with EDX, TEM, Raman, XPS, UV-DRS and PL. The XRD pattern exhibited the diffraction peaks of g-C3N4 (hexagonal) and CuO (monoclinic) and Fe3O4 (FCC) and the CuO-Fe3O4 mixing of monoclinic and cubic phases along with CuO (−111) direction. The TEM analysis shows the dispersion of CuO-Fe3O4 on g-C3N4 sheets in the CuO-Fe3O4/g-C3N4 (50:50) NC. From the XPS spectra, the oxidation states of Cu2p, Fe2p, O1s, C1s, and N1s, as well as their orbital bonding, are analyzed. The bandgap was calculated by photon energy vs ILD and (F(R∞)hv)2 by using UV-DRS spectrum. The catalyst, CuO-Fe3O4/g-C3N4 (50:50)@NF had a low overpotential of 69 mV at the current density of 10 mA cm2, close to the value of 20 % Pt (45 mV). A chronoamperometry test demonstrated that CuO-Fe3O4/g-C3N4 (50:50)@NF works efficiently for more than 30 h at a high current density of 15 mA cm−2 indicating the strong stability of CuO-Fe3O4/g-C3N4 (50:50)@NF. The maximum photocatalytic degradation efficiency against Rhodamine-B was found to be 99.51 % and crystal violet degradation efficiency is 98.02 % by using CuO-Fe3O4/g-C3N4 (50:50).
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The different inhibition behavior of imidazoline quaternary ammonium salt for high-pressure CO2 flow accelerated corrosion of carbon steel gradual contraction and gradual expansion tubings was ...unveiled combing high pressure dynamic in situ electrochemical methods and microstructure characteristics analysis. It is manifested that there is no noticeable inhibition effect in high CO2 partial pressure environments at extremely low inhibitor concentration. At low inhibitor concentration, the polarization resistance and inhibition efficiency increase firstly and then decrease along the flowing direction of gradual contraction tubing. However, the polarization resistance generally drops along the gradual expansion tubing. As the inhibitor concentration of the corrosion inhibitor is further increased, the polarization resistance and inhibition efficiency are reduced in a whole along the gradual contraction tubing. Nevertheless, the polarization resistance is raised, followed by a fall along the flowing direction of gradual expansion tubing. The inhibition effect at the top and the bottom of gradual contraction tubing exhibits symmetry while it is asymmetrical at the top and the bottom of inclination section in gradual expansion tubing. The distinct inhibition effect at different inhibitor concentration is relevant to flow characteristics of fluid at gradual contraction tubing and gradual expansion tubing. The findings could provide valuable guidance for the protection of flow accelerated corrosion at gradual contraction tubing and gradual expansion tubing under high CO2 partial pressure conditions.
•The inhibition behavior of IQAS for high-pressure CO2 FAC of carbon steel GC and GE tubings was studied.•The Rp and IE along GC tubing and GE tubing exhibits significantly distinction at different inhibitor concentration.•The Rp values at the top and bottom of GC tubing are similar while they are quite different at GE tubing.•Hydrodynamics at GC/GE tubing play a vital role in inhibition behavior of IQAS at different inhibitor concentration.
A 51-year-old man with alcoholic liver cirrhosis was hospitalized for treatment of rectal varices. 3D-CT revealed that the rectal varices’ inflow vessel was the superior rectal vein─branching from a ...mesenteric vein─and outflow vessels were the middle and inferior rectal vein draining into the internal iliac vein. The diameter of the inferior mesenteric vein was thinner than that of the left gastric vein. Therefore, it was speculated that the variceal blood flow rate would be low, and endoscopic injection sclerotherapy (EIS) was selected as the treatment method. EIS was performed using 5% ethanolamine oleate with iopamidol. Endoscopic varicealography during injection sclerotherapy (EVIS) clearly showed the rectal varices, superior rectal vein, and inferior mesenteric vein. After treatment, complete embolization of the rectal varices and inflow vessels was confirmed by contrast enhanced CT, and endoscopy revealed disappearance of the rectal varices. This case of rectal varices was successfully treated using EIS.
Electrochemical impedance spectroscopy (EIS) is a widely used experimental technique for characterising materials and electrode reactions by observing their frequency-dependent impedance. Classical ...EIS measurements require the electrochemical process to behave as a linear time-invariant system. However, electrochemical processes do not naturally satisfy this assumption: the relation between voltage and current is inherently nonlinear and evolves over time. Examples include the corrosion of metal substrates and the cycling of Li-ion batteries. As such, classical EIS only offers models linearised at specific operating points. During the last decade, solutions were developed for estimating nonlinear and time-varying impedances, contributing to more general models. In this paper, we review the concept of impedance beyond linearity and stationarity, and detail different methods to estimate this from measured current and voltage data, with emphasis on frequency domain approaches using multisine excitation. In addition to a mathematical discussion, we measure and provide examples demonstrating impedance estimation for a Li-ion battery, beyond linearity and stationarity, both while resting and while charging.
Atmospheric corrosion and the resulting mechanical property degradation of 2524-T3 aluminum alloy in marine environments with different environmental factors are investigated. 2524-T3 aluminum alloy ...exhibits the most severe corrosion in tropical marine atmosphere, attributed to the highest temperature, humidity, rainfall, Cl- deposition rate, and the longest time of wetness. The EIS results are closely related to the corrosion evolution process. The degradation sensitivity indexed by elongation, reduction-in-area, and tensile strength is correlated with the average corrosion-induced surface defect depth (D′ave), while the elasticity modulus is related to the maximum corrosion penetration depth (Dmax).
•Atmospheric corrosion induced mechanical property degradation of 2524-T3 aluminum alloy is studied.•High temperature and Cl- deposition rate result in a deeper corrosion defect in tropical marine atmosphere.•The change of elasticity modulus is correlated with maximum corrosion defect depth.•The degradation of elongation and tensile strength shows a direct relationship with the average corrosion depth.
This study focuses on the preparation and characterization of a novel anticorrosion pigment based on decanoate anions (C10‐) intercalated within layered double hydroxide (LDH) MgAl. The LDH-NO3, ...LDH-C10 were synthesized by a simple co-precipitation method and analyzed by XRD, infrared spectroscopy, thermogravimetry and electronic microscopy. The LDH-C10 pigment with a basal distance of about 20 Å was consistent with the arrangement of C10 anions in bilayer. The inhibition efficiency of the LDH-C10 pigment in electrolyte and in alkyd resin paint was studied by electrochemical impedance spectroscopy and potentiodynamic techniques. The pigments act as a C10− nanocontainer, which release the C10− anions in contact with chloride ions that lead to the formation of a passive layer on steel. In alkyd resin, the LDH-C10-enriched organic coating exhibit very interesting anticorrosive performance in NaCl electrolyte during 40 days of immersion.
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•One of the pioneering studies to explore the high-temperature corrosion of AM SS316L in CO2-saturated brine.•SS316L samples nearly free of defects were fabricated using LPBF with ...optimal process parameters.•The corrosion rate increased fivefold with a temperature rise from 25 to 70 °C.•Increase in temperature led to increased susceptibility to pitting corrosion.•Repassivation of the protective film became challenging at elevated temperatures.
The present study investigates the influence of temperature on corrosion of AM SS316L in CO2 saturated brine solution. As the temperature increased from 25 °C to 70 °C, the corrosion rate rose nearly fivefold, from 1.78 to 10.06 mpy. The pitting potential decreased from 818 mV to 450 mV, with the gap between |Epit – Erep| widening from 669 mV to 853 mV. EIS results corroborated these results, revealing a decline in Rct from 4755 to 858 Ωcm2 and an increase in Yct from 38 to 119 snΩ-1cm−2. Subsequent surface morphology analysis post-corrosion testing revealed increased corrosion severity with rising temperature. In summary, elevated temperature led to increased corrosion rates, more susceptibility to pitting corrosion, and hindered repassivation.
The influence of an applied mechanical pressure on the electrochemical performance and the aging of 1.4 Ah graphite/NMC622 stacked Lithium-ion battery cells (LiBs) is investigated comprehensively on ...the electrode and the full cell level. Pressure dependent ionic pore resistance measurements reveal an increase of the ionic pore resistance in both, the anode and the cathode of 6% and 2.9%, respectively at a pressure of 0.84 MPa. Compressibility measurements expose an interesting nonlinearity of the compressibility and the number of layers in an electrode stack, which must be considered for the cell application. The applied pressure improves the electrical contact in the cell. However, by the increase of both, the ionic pore resistance and the charge transfer resistance, the reversible capacity loss is strongly dependent on the applied C-rate during the cycling. For C-rates above 0.8C the polarization losses of the compressed cells are around 7.3% in comparison to 2.1% for the uncompressed cells. Contrariwise, for C-rates below 0.8C the compression of the cells is beneficial and leads to a capacity increase of 2.0% compared to the uncompressed cells. The subsequent post-mortem analysis demonstrates the negative influence of the absence of a homogeneous pressure distribution within the uncompressed cells.
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•Mechanical pressure improves the electrical contact in Li-ion batteries.•Reduced ionic pore resistance gets dominant in compressed cells at high C-rates.•Compressibility is strongly dependent on the number of layers.•Uncompressed Li-ion batteries tend to Li deposition.
The adsorption and corrosion inhibition mechanism of Vitamin B1 on mild steel in 0.5M HCl solution were studied using electrochemical, spectroscopic, and microscopic techniques. The studied organic ...compound acts by adsorption on the metal surface via physical and chemical interactions, which reduces both anodic and cathodic reactions. The inhibitor film evenly distributes over the steel surface and is stable. Display omitted
•Vitamine B1 inhibits corrosion of mild steel in 0.5M HCl solution.•Vitamine B1 acts by reducing the rates of both anodic and cathodic reactions.•The inhibitor film is very stable at low anodic and cathodic potentials.•The corrosion mechanism is charge transfer controlled.•The adsorption of Vitamine B1 is the mixed type of chemical and physical interactions.
The corrosion inhibition mechanism and the stability of Vitamin B1 (VitB1) on mild steel in 0.5M HCl solution were investigated. Surface of the steel after exposing to test solutions were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy dispersive X-ray spectroscopy (EDX). The stability of the inhibitor film was investigated by electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and cyclic voltammetry (CV) techniques. It was found that VitB1 acts by adsorption on mild steel via physical and chemical interactions and a protective film formation. The inhibitor film evenly distributes over the steel surface and is stable.
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