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Cyclic voltammetry and impedance studies of undoped diamond films

Abstract

The undoped, polycrystalline diamond films were deposited on tungsten wire substrates by hot filament chemical vapor deposition (HF CVD), using a precursor gas mixture of methanol with excess of hydrogen. The morphology and quality of the as-deposited films were monitored by scanning electron microscopy (SEM) and Raman spectroscopy. The surface morphology analyzed by SEM resembles a continuous and well faceted diamond film. Raman results showed essential differences in qualities of diamond films grown at different hydrocarbon concentrations. The electrochemical properties of diamond electrodes were examined with cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS). The CV experiments revealed a large chemical window (>∼4.3 V) of undoped diamond. Analysis of the ferrocyanide-ferricyanide couple at a diamond electrode suggests some extent of electrochemical quasi-reversibility, but the rates of charge transfer across the diamond substrate interface vary with diamond quality.

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Dopamine detection using mercaptopropionic acid and cysteamine for electrodes surface modification

Introduction Cyclic Voltammetry (CV) is famous for its simplicity for the functionality and for the high detailed information content for potentio-dynamic electrochemical measurement. Cyclic voltammogram trace is obtained when the current at the working electrode is plotted graphically against the applied potential for that respective counter electrode. CV analysis gives the best study not only for the electrochemical properties of an analyte but also for the oxidation and reduction patterns and rates for specific species deposition on the electrode in a

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Comparative Assessment of the Analytical Parameters in Ascorbic Acid and Sulphite Assay at a Spectrographic Carbon Working Electrode

. Electroanalytical techniques for the determination of sulphite preservative: an editorial. Biochemistry & Analytical Biochemistry,3(2) e151. doi: 10.4172/2161-1009.1000e151. Pisoschi A.M., 2017. The investigation of the viability of the Pt electrode in sulphite cyclic voltammetry assay. Scientific Works. Series C. Veterinary Medicine, LXIII (1): 21-24. Pisoschi A.M., Danet A.F., Negulescu Gh.P., 2006. Glucose determination by cellophane-based and nylon-based enzymic electrodes; application on juices and wine analysis. Electronic Journal of

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Electrochemical oxidation of salicylhydroxamic acid on Pt electrode

Abstract

The electrochemical oxidation behavior of salicylhydroxamic acid (SHAM) on a Pt electrode was investigated in aqueous solution of different pHs, containing 10 mM of SHAM, at 25°C, by cyclic voltammetry technique. The results indicate that the SHAM was oxidized more easily in alkaline medium than acidic and neutral mediums, and the oxidation peaks of SHAM shifted toward lower potential values by increasing pH values. The SHAM electrooxidation involves an irreversible transfer of one or two electron, depending on the pH of solution. If solution pH is lower than 3 and higher than 7, the two electron transfer is involved in the electrooxidation. While, from pH=3 to pH=7, the SHAM electrooxidation involves an irreversible transfer of one electron and two protons in the first step, in agreement with the one step one-electron mechanism. The effect of SHAM concentration on the electrode reaction was investigated in artificial saliva solution. SHAM gives a single irreversible oxidation wave over the wide concentration range studied. Possible mechanism of SHAM electrooxidation was proposed.

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Electrochemical Studies of Interactions Between Fe(II)/Fe(III) and Amino Acids Using Ferrocene-Modified Carbon Paste Electrode

Abstract

The electrochemical behavior of an Fe(II)/Fe(III) redox couple in the presence of various selected amino acids has been studied using ferrocene-modified carbon paste electrode at pH = 7.4. Because of Fe(II)/Fe(III) solubility issues at physiological pH, ferrocene was used as a source of iron. Anodic oxidation of iron (pH = 7.2) occurred at 0.356 V and cathodic oxidation at 0.231 V, both vs Ag|AgCl. Treatment of the voltammetric data showed that it was a purely diffusion-controlled reaction with the involvement of one electron. After addition of amino acids, potential shifts and current changes can be observed on the voltammograms. Cyclic voltammetry experiments revealed the capability of amino acids to change the electrochemical behavior of the Fe(II)/Fe(III) redox couple.

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CVD diamond layers for electrochemistry

Abstract

Diamond electrodes of different morphologies and qualities were manufactured by hot filament chemical deposition (HF CVD) techniques by changing the parameters of diamond growth process. The estimation of diamond quality and identification of different carbon phases was performed by Raman spectroscopy measurements. The effect of diamond quality and amorphous carbon phase content on the electrochemical response of an obtained diamond electrode in 0.5 M H2SO4 as supporting electrolyte was investigated by cyclic voltammetry with [Fe(CN)6]4−/3− as a redox probe. The kinetic parameters such as catalytic reaction rate constant k0 and electron transfer coefficient α were determined. The obtained results show that the analytical performance of undoped diamond electrodes can be implemented just by the change of diamond layers quality.

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Corrosion Testing of Additively Manufactured Metals and Biomedical Devices

Abstract

Additive manufacturing (AM) is becoming increasingly important, making it possible to produce a product in a short time, to specific individual requirements, and even in the presence of the customer. This research is related to direct metal laser sintering of additive manufacturing. This new technology is increasingly being used in more sectors, for example in biomedical industry, where a damaged product can potentially endanger human life. Corrosion tests were carried out during our research. Cyclic voltammetry curves and corrosion rates were determined with a potentiostat. Two typical biocompatible implant materials were compared, a cobalt chromium alloy (powder metallurgy) and a titanium alloy (3D printed). The results will help in specifying the corrosion properties of additively manufactured materials.

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Polystyrene/magnetite nanocomposite synthesis and characterization: investigation of magnetic and electrical properties for using as microelectromechanical systems (MEMS)

a good capability to incorporate magnetite nanoparticles [ 30 , 34 ]. Polystyrene is not conductive inherently but it can become conductive by adding critical amount of conductive nanoparticles to it [ 35 ]. In this study, a novel method for preparation magnetite/polystyrene nanocomposite is presented. Electrical properties of the nanocomposite were studied by cyclic voltammetry to know the usefulness of the nanocomposite for sensor applications. The FESEM images were taken to study the size and the shape of the nanocomposite. The properties of prepared

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Antioxidant Properties, Acrylamide Content and Sensory Quality of Ginger Cakes with Different Formulations

-73. Capuano E., Ferrigno A., Acampa I., Serpen A., Açar Ö.Ç., Gökmen V., Fogliano V., Effect of flour type on Maillard reaction and acrylamide formation during toasting of bread crisp model systems and mitigation strategies. Food Res. Int., 2009, 42, 1295-1302. Chevion S., Chevion M., Chock P.B., Beecher G.R., The antioxidant capacity of edible plants: extraction protocol and direct evaluation by cyclic voltammetry. J. Med. Food 1999, 2, 1-11. Ciesarová Z., Kukurová K., Bednáriková A., Morales J.F., Effect of heat

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Synthesis and characterization of hollow V2O5 microspheres for supercapacitor electrode with pseudocapacitance

and exhibited a high initial reversible capacity of 256 mAh·g –1 at a current density of 300 mAh·g –1 . Su et al. [ 31 ] reported HVOM prepared from vanadyl ethylene glycolate (VEG) hollow nanospheres which demonstrated a good high-rate capability and cycling stability. However, HVOM used as the cathode material for SCs has rarely been reported. Yang et al. [ 22 ], based on the results obtained by the cyclic voltammetry (CV) method, reported that hollow V 2 O 5 spheres exhibited the maximum capacitance of 479 F·g –1 at 5 mV·s –1 when used as SCs electrodes in 5

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