The industrial chlorate process has traditionally used chromium(VI) as an electrolyte additive for high Faraday efficiency. However, due to its recognized toxicity and carcinogenic properties, the EU ...has regulated its usage, prompting the need for alternative approaches. In this study, we propose the adoption of a polymeric membrane-coated cathode (MCC) as a straightforward yet highly efficient solution to enhance the selectivity of the hydrogen evolution reaction (HER) in chlorate electrolysis. Proof-of-concept MCCs were fabricated by coating roughened titanium substrates with cation and anion exchange membrane layers, which function as selective barriers for anodic hypochlorite species. The study revealed that a thin membrane coating on the electrode surface effectively suppressed the permeation of anodic intermediates, without compromising the current density for HER. By optimizing the coating layer thickness and substrate surface properties of MCC, the chlorate electrolysis cell demonstrated an impressive Faradaic efficiency of up to 95% at a current density of 150 mA/cm², while maintaining exceptional stability. The outcome of this study can potentially advance the feasibility of industrial chlorate production in meeting regulatory requirements and effectively mitigating environmental consequences.
Abnormally high NO2− levels from the excessive use and in appropriate disposal of high nitrogen content chemicals can disrupt the natural ecosystem, leading to cancer and other fatal diseases in ...animals and humans. Hence, it is imperative to develop a reliable NO2−sensor for monitoring nitrite levels in aqueous systems. In this work, a non-enzymatic electrochemical nitrite (NO2−) sensor has been developed by modifying a glassy carbon electrode (GCE) with Pt nanoparticle (PtNP) coated carboxylated activated jute carbon (PtNP_CAJC/GCE). The carboxylated activated jute carbon material was achieved using a thermochemical synthesis pathway, while the PtNP coating was prepared via an ultrasonication pathway. The important feature of this work was to understand the electron transfer mechanism of NO2− using electrocatalysis. The electrochemical probe, PtNP_CAJC/GCE, was tested for the amperometric detection of NO2− in phosphate buffer solution at pH 7.0 under ambient conditions. NO2− sensing on the surface of the electrocatalyst was found to follow a two-electron transfer process and the second electron transfer was the rate-determining step. A computational CV simulation was carried out based on the evaluated kinetic parameters. In addition to the superior stability observed on repeated use and storage, the probe demonstrated excellent efficacy in detecting the NO2− over a wide linear range (4.99 μM−4.23 mM) with high selectivity in the presence of common interfering additives. The PtNP_CAJC/GCE probe was successfully tested for the detection of NO2− in real samples, viz., tap water employing an amperometric method.
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•Pt nanoparticle coated carboxylated activated jute carbon was synthesized.•The as-prepared sensor shows a wide linear range from 4.99 μM to 4.23 mM.•The sensor also shows high selectivity and sensitivity (1.11 × 10−7 A cm−2 μM−1).•The cyclic voltammetry data was simulated based on the evaluated kinetic parameters.•The sensor shows good stability, reproducibility, and high resistance to interfering species.
•A fast calculation of electrical parameters of coated grounding electrodes.•Simulating the effect of oxidation by modifying the electrode radius.•Introducing the Coated Electrode Equivalent Radius ...by simple expression.•Conventional calculation methods are used by modifying the radius of the coated electrodes.
The effect of an oxide layer or any conductive material layer surrounding the electrode surface on the performance of grounding system is studied in this paper. The boundary elements method applied to the electrode surface together with the Equivalent Surface Charge Distribution model to assess the contribution of the material-soil interface are used to compute the grounding resistance of an electrode buried in a semi-infinite soil and energized by a low frequency current. Due to the high computation time required to apply the numerical method to find the solution of the problem, the Coated Electrode Equivalent Radius is introduced from the study of the grounding resistance as a tool to simulate the effect of the material layer on the electrode. This equivalent radius is a function of the thickness of the material layer and can be used in common methods for calculating parameters of a grounding system such as grounding resistance and step and touch potentials. The proposed expression for the equivalent radius is tested in several synthetic examples and also in a real case. Some of the tests carried out are also compared with the results of using commercial software.
Enhancing the operational efficacy of electrical discharge machining (EDM) is crucial for achieving optimal results in various engineering materials. This study introduces an innovative solution—the ...use of coated electrodes—representing a significant advancement over current limitations. The choice of coating material is critical for micro-EDM performance, necessitating a thorough investigation of its impact. This research explores the application of different coating materials (AlCrN, TiN, and Carbon) on WC electrodes in micro-EDM processes specifically designed for Ti-6Al-4V. A comprehensive assessment was conducted, focusing on key quality indicators such as depth of cut (Z), tool wear rate (TWR), overcut (OVC), and post-machining surface quality. Through rigorous experimental methods, the study demonstrates substantial improvements in these quality parameters with coated electrodes. The results show significant enhancements, including increased Z, reduced TWR and OVC, and improved surface quality. This evidence underscores the effectiveness of coated electrodes in enhancing micro-EDM performance, marking a notable advancement in the precision and quality of Ti–6Al–4V machining processes. Among the evaluated coatings, AlCrN-coated electrodes exhibited the greatest increase in Z, the most significant reduction in TWR, and the best OVC performance compared to other coatings and the uncoated counterpart.
In high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs), it is important that the structure of the electrode catalyst layer is formed uniformly. To achieve this, the binder must be ...well dispersed; however, polytetrafluoroethylene (PTFE), which is commonly employed in the preparation of HT-PEMFCs, is difficult to disperse during electrode manufacture due to its high hydrophobicity. In this study, we fabricate electrodes containing a surfactant to improve the dispersion of the PTFE binder and to enhance reproducibility during electrode manufacture. The electrodes are commonly prepared via a bar coating method, which is known to exhibit poor dispersion due to the small amounts of solvent employed compared to the spraying method. We then compare the properties of the obtained electrodes prepared in the presence and absence of the surfactant through physical and electrochemical characterization. It is found that the electrode containing the surfactant is structurally superior, and its single cell performance is significantly higher (i.e., 0.65 V at 0.2 Am cm−2). The single cells are suitable for operation at 150 °C using H2/air at atmospheric pressure and a total platinum loading of 2.0 mg cm−2.
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•Bar-coated electrodes were prepared in the presence and absence of a surfactant.•The surfactant improved the dispersion of the polytetrafluoroethylene binder.•The reproducibility and efficiency of the triple phase boundary were improved.•The use of a surfactant gave superior electrode performances in single cell system.•This system was applicable for the preparation of large-scale bar-coated electrodes.
Abstract The following article presents experimental use of different ways of inguinal connecting of aircraft elements using TIG (Tungsten Inert Gas), MAG (Metal Active Gas) and arched coated ...electrode. The object of the research were samples of rotorcraft elements, which were connected to each other by TIG, MAG methods and the coated electrode. The main aim of the research was to determine selected mechanical properties in particular hardness and strength of inguinal joints and then, based on the tests carried out, the best methods were selected.
The short service life of the Ti/BDD coated electrode is the main reason that limits its practical use. In this paper, the effect of structural change on the service life was studied using Ti/BDD ...coated electrodes prepared with the arc plasma chemical vapor deposition (CVD) method. It was found that the microstructural defects and corrosion resistance of BDD coatings were the main factors affecting the electrode service life. By optimizing the process parameters in different deposition stages, reducing the structural defects and improving the corrosion resistance of the BDD coating were conducted successfully, which increased the service life of the Ti/BDD coated electrodes significantly. The lifetime of the Ti/BDD samples increased from 360 h to 655 h under the electrolysis condition with a current density of 0.5 A/cm2, with an increase of 82%.
Conducting polymer-coated electrodes have been studied as one of the most suitable solid electrodes in organic membrane for fabrication of all-solid ion-selective electrodes or the voltammetric ...devices for the ion transfer at the liquid-liquid interface. In the present work, we report that the partially oxidized conducting polymer-coated electrode—the 50% oxidized poly(3,4-ethylenedioxythiophene), PEDOT, -coated indium-tin oxide glass electrode, ITOE — has high potential stability, reproducibility of the potential and low susceptibility to current flowing in a hydrophobic organic phases such as 1,2-dichloroethane, DCE, and 2-nitrophenyloctylether, NPOE; potential drift in open circuit potential for 200 h in DCE and NPOE were <11 mV, reproducibility of the electrode potential in DCE and NPOE were ±10 mV, and the maximum redox capacity allowing potential drift <10 mV were 0.100 mC cm−2 in DCE and 0.113 mC cm−2 in NPOE, respectively. These results imply that the 50% oxidized PEDOT-ITOE functions as both the reference electrode and the counter electrode in organic membrane for an amperometric ion sensor. The oxidation ratio in the PEDOT film was the primary factor influencing the potential stability. The optimum oxidation ratio was evaluated from the dependence of the absorption spectra of the conducting polymer on the applied potential, and adjustment method of the optimum oxidation ratio was proposed. The 50% oxidized PEDOT-ITOE is stable in air within 200 h, but oxidation by air cannot be ignored for a longer time period of 30 days. The proposed 50% oxidized PEDOT-ITOE is applicable for incorporation in a semi-disposable device used for 1 week. Effect of the oxidation ratio in PEDOT on the voltammetry for the ion transfer was also examined, and the 50% oxidized PEDOT-ITOE was usable in voltammetric thin layer cell of the two-electrode system based on the ion transfer at the water-organic membrane interface.
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•Oxidation ratio of poly(3,4-ethylenedioxythiophene), PEDOT, largely effects on potential stability and reproducibility of the PEDOT-coated electrode.•Formal redox potential of PEDOT was evaluated on the basis of dependence of the absorption spectrum on the applied potential.•The 50% oxidized PEDOT is able to be redox buffer and used in a reference and/or counter electrode in organic phase.•Oxidation equilibrium between PEDOT-electrode and oxygen involved in air resulted in the oxidation ratio of 65% in PEDOT.•Thin layer cell with the 50 % oxidized PEDOT-electrode gave ideal voltammogram for the ion transfer.
An affordable and highly efficient graphite‐coated electrode was developed and applied in this work as a compelling alternative to other modified electrodes in catechol determination. Electrode ...modification involved a simple deposition process using a commercial graphite dispersion, Aquadag®Acheson. Morphological and electrochemical studies revealed the formation of a uniform layer with enhanced surface area and significant conductivity. Catechol quantification was successfully achieved in the linear concentration range extended up to 80 μmol L−1 with a detection limit of 0.5 μmol L−1 under optimized conditions (pH 7 and an accumulation time of 2 min). Spike‐and‐recovery experiments validated the accuracy of the determination. Unlike hydroquinone, structurally similar compounds such as phenol and resorcinol did not interfere with catechol analysis. The interference posed by hydroquinone was addressed by derivative treatment of the voltammograms allowing peaks resolution.
This study introduces an economical and efficient graphite‐coated electrode fabricated using Aquadag®Acheson commercial graphite dispersion. It exhibits significant potential, particularly in catechol determination, demonstrating strong analytical capabilities across a broad concentration range and robustness against interferences. Thus, the graphite‐coated electrode offers an innovative and compelling alternative for diverse electroanalytical applications.
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