We prepared the novel materials of Y-doped SnO2-CdO nanocomposite, Y-SnO2 and CdO nanoparticles by a facile chemical technique. Structural, crystallite size and lattice parameters are investigated by ...XRD spectrometer. The morphologies show highly aggregated due to tiny particles of Y3+, Sn4+ and Cd2+ were present in nanocomposite were analyzed by HR-TEM. The presence of a functional group of elements was identified by FT – IR spectrometer. The X-ray photoelectron spectroscopy (XPS) is used to analyze the ionization state of elements, composition and purity of the nanocomposite. Optical properties such as lower absorption edge, widened band gap and particle size were studied by UV – visible spectrometer and Photo luminescence (PL) was used to determine the violet emission of nanocomposite. At room temperature, ferromagnetism was obtained in the nanocomposite was studied by VSM. From Cyclic-Voltammetry (CV), the nanocomposite has behave as pseudocapacitance that occurs in the potential range between – 0.7 V to 0.5 V. Electrochemical impedance spectroscopy (EIS) was investigated for impedance, dielectric, electric modules and a.c conductivity of nanocomposite. Because of its optical, magnetic, and electrochemical characteristics, the Y-SnO2-CdO nanocomposite is therefore ideally suited for a variety of possible multifunctional applications.
•A simple chemical method was used to prepare the Y-doped SnO2–CdO for the first time.•They have a mixed rutile tetragonal - cubic structure and a quasi-spherical shape.•Enhanced photocatalytic activities and ferromagnetic behaviour were obtained.•At room temperature, the constant pseudo capacitance occurs for several scan rates.•They have large impedance, very low dielectric loss and non-Debye relaxation.
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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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.
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.
•Trace amounts of Ce significantly refine the alloy grain size;•The addition of trace amounts of Ce improves the corrosion resistance of the alloy;•The strong surface activity of Ce inhibits the ...adsorption of Cl− on the metal surface；
The impact of trace Ce doping on the pitting behavior of Fe40Ni20Co20Cr20 high-entropy alloy in a 3.5 wt% NaCl solution was examined. The results indicate that the addition of trace Ce elements leads to a notable reduction in grain size and improved corrosion resistance of the alloy, the critical pitting potential of the alloy increased to 428 mv, and the corrosion resistance of the passivation film was significantly enhanced. This improvement can be mainly attributed to the strong surface activity of Ce, which promotes the formation of Cr2O3 in the passivation film, resulting in a more stable and protective film layer. The ΔE (difference between corrosion potential and zero charge potential) of the high-entropy alloys (HEAs) was negative, indicating a decrease in the adsorption capacity of the electrochemical interface for Cl−. This reduction helps to mitigate pitting corrosion on the surface of the passivation film caused by Cl− erosion.
The hydration process of blended cementitious materials is primarily affected by the effect mechanism of supplementary cementitious materials. This study utilizes electrochemical impedance ...spectroscopy (EIS) method to investigate the hydration kinetics of cementitious materials incorporating metakaolin (MK), quartz (Q) and limestone powder (LS). The experimental results reveal the influence of MK+Q+LS on the hydration kinetics, phase assemblage, and microstructure of the blended systems. Besides, the electrochemical impedance response of blended cement materials exhibits variation based on the MK contents and the curing age. Furthermore, the resistance of the continuously connected micro-pores (Rccp) in the blended cementitious material progressively increases throughout the hydration process. The inclusion of MK reduces the Rccp values at early ages, while contributes to an increase in Rccp values from 7 days onward. Additionally, positive correlations are established between the Rccp value and compressive strength/heat release across different MK contents and curing ages. The combination of Rccp values and other characterization method can effectively reveal the microstructure evolution process. Therefore, as a nondestructive method, EIS can be effectively applied to predict the hydration of cementitious materials and the mechanical properties.
•System with 40 % MK and 60 % quartz, simulated as low-grade calcined clay, exhibit comparable compressive strength to OPC.•The Rccp value, associated with the connected pores, exhibits a correlation with compressive strength and heat release.•Rccp values is related with the filler effect, carboaluminate formation effect and the pozzolanic reaction effect of MK.
The inhibition action of Aloe Vera leaf extract as environmentally friendly inhibitor for the corrosion protection of stainless steel in 1M H2SO4 solution was studied by electrochemical techniques as ...well as scanning electron microscope. The results of linear polarization and electrochemical impedance spectroscopy proved the effectiveness of Aloe Vera extract as concentration increased. Corrosion inhibition of Aloe extract was also studied by electrochemical noise (EN). Employing EN, different aspects like transient analysis, noise resistant and characteristic charge were characterized. Moreover, a literature review of Aloe Vera characterization using high-performance liquid chromatography and GC-MS was carried out.
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