Type Of Carbon Electrode Research Articles

Électrosynthèse de films de polyparaphénylène déposés sur carbones

This present work deals with the formation of polyparaphenylene (PPP) electrodes in which the polymer is associated with conductive carbons. Regular and reproducible coatings of PPP on different types of carbon electrodes were obtained by catalytic electrosynthesis (Fauvarque method) and were examined by electron microscopy. Electrochemical properties of PPP, coated on conductive carbons, were studied in sulfolane-NBu4BF4 electrolyte. Coatings on carbon lead to a good cyclability and a high apparent current density (as high as 2 mA/cm2). Key words : conductive polymers, polyparaphenylene, electrolytic coating.

The stabilising influence of hematin on the properties of the oxygen-sensitive carbon electrode

Carbon films obtained by the spray-pyrolysis technique were applied to the construction of electrodes sensitive to dissolved oxygen. Four types of the carbon electrodes were examined: virgin carbon from polyfurfuryl alcohol (A), virgin carbon with a hematin film (B), Fe-modified carbon (C), and Fe-modified carbon covered with a film of hematin (D). The layer of hematin basically played the role of an accumulator of physically adsorbed oxygen. The application of the hematin film yielded carbon electrodes of better stability. Such an electrode exhibited the capability for the very strict two electron reduction of oxygen molecule in the relatively wide range of oxygen concentration in water. Except for electrochemical tests, all types of carbon electrodes (including the hematin covered one) were examined using XP spectroscopy, FT-IR spectroscopy, and SE microscopy.

Applications of Diamond Thin Films in Electrochemistry

Electrochemical reactions typically involve electron transfer between an electrode and a dissolved chemical species at a solid-electrode/liquid-electrolyte interface. Three broad classes of electrochemical applications may be identified: (1) synthesis (or destruction), in which an applied potential is used to bring about a desired chemical oxidation or reduction reaction; (2) analysis, in which the current/potential characteristics of an electrode are used to determine the type and concentration of a species; and (3) power generation. These broad types of applications require stable, conductive, chemically robust, and economical electrodes. Diamond electrodes, fabricated by chemical vapor deposition, provide electrochemists with an entirely new type of carbon electrode that meets these requirements for a wide range of applications.The first reports of electrochemical studies using diamond were in the mid-1980s. During the past several years, the field has attracted increasing attention. This review summarizes the electrochemical properties of diamond that make it a unique electrode material and that distinguish it from conventional carbon electrodes.

Electrochemical behavior of metallothioneins at mercury and carbon electrodes

Rabbit Cd, Zn-metallothionein (Cd, ZnMT), synthetically prepared Cd-metallothionein (CdMT), and apometallothionein (apoMT) have been studied at a mercury electrode and at two types of carbon electrode. At the mercury electrode, different metallothioneins can only be distinguished in cases where their contact with the mercury electrode surface is short. With prolonged time, a mercury compound is formed and its peaks prevail over all the original MT peaks. This conclusion is supported by comparison with apoMT voltammetry at mercury and carbon electrodes. At glassy carbon or carbon composite electrodes, apoMT can be distinguished and determined in the presence of MTs. For both MTs studied, the formation of metal-free S groups can be observed with prolonged electrolysis at negative potentials; this process is reversible and after several CV cycles, the original structure is reestablished.

Spectroscopic ellipsometry of carbon electrodes during electrochemical activation

The effect of electrochemical activation on three types of carbon electrode, namely glassy carbon (GC), pyrolytic graphite (PG) and highly oriented pyrolytic graphite (HOPG), was investigated in situ using spectroscopic ellipsometry. The activation procedure consisted of a certain number of potential cycles between −0.5 and 1.86 V with respect to a saturated calomel electrode with a scan rate of 150 mV s -1 in 1 M H 2SO 4. For GC and PG electrodes the spectroscopic ellipsometry results can be well described by assuming a porous surface film, consisting of a mixture of GC or PG and electrolyte on top of the bulk substrate. While a film with increasing thickness and a constant void fraction of 80% is obtained for GC during prolonged activation, a decreasing film thickness with increasing void fraction results for PG. For HOPG no film formation is observed. The activation of HOPG leads to irreversible intercalation, indicating delamination at exposed edges.

Carbon fiber as an electrode material.

A new type of carbon electrode is introduced. The electrode consists of a bundle of carbon fibers, each fiber having a diameter of approximately 8 jim. In contrast to most electrodes, this electrode is flexible. The fabrication of the electrode is described, and a method is given to determine the apparent stimulating area.

Observation about the Application of Arc-Air Gouging Process in Shipyard

It is a well recognized fact that the arc-air gouging process is more advantageous than the pneumatic chipping method in point of economy. In carring out the gouging in Japanese shipyards there arises an important problem because their electric source is of alternating current whereas the arc-air gouging should be of direct current.Considering this special situation of Japanese shipyards, authors have made different types of carbon electrodes for arc-air gouging in order to investigate their applicabilities and ascertained the usefulness of carbon electrode for use with alternating current in shipyards.