carbon nanotubes

By cyclic voltammetry and rotating disk electrode investigated the stability of the composite catalyst Pt/C–CNT from electrochemical action through multiple changes of the electrode potential from –150 to 1000 mV vs. silver chloride reference electrode. Investigated: the dynamics of the electrochemically active surface area of platinum and electrode in whole, change of amount of quinone groups, change in density of the kinetic current reduction of air oxygen on the surface of the catalyst.

Catalysts for oxygen reduction in the alkaline electrolyte based on multi-walled carbon nanotubes modified with urea and phthalocyanines of iron, cobalt and palladium were synthesized and studied. Physicochemical studies of the surface of the synthesized materials were carried out using porosimetry, Raman spectroscopy, X-ray phase analysis and X-ray photoelectron spectroscopy. The catalyst doped with metal phthalocyanines (MWCNT(Urea)_CoPc_FePc_Pd) has the largest surface area.

A method for producing nitrogen-doped carbon nanotubes was tested. Polyaniline, chemically synthesized on the surface of nanotubes with subsequent carbonization, was used as a source of nitrogen. The electrochemical characteristics of the electrodes based on the obtained carbon material for the hybrid supercapacitors with the acidic electrolyte were studied. It was shown that nitrogen doping of carbon nanotubes increases the capacitive characteristics of the electrodes. 

The influence of the composition, the thickness and the surface morphology of Li3V2(PO4)3 or Li4Ti5O12 based electrode composites with carbon nanomaterial and polyvinylidene fluoride on their electrochemical performance was examined. The thickness and the surface morphology of the electrodes were jointly controlled by rolling with different gaps and monitored using 3D laser microscopy and scanning electron microscopy.

Ethanol electrooxidation catalyst PtSn (3:1, 40% Pt) on pyrolytic double-walled carbon nanotubes as a carrier was synthesized by means of modified polyol method. Electrocatalytic activity of the synthesized catalyst in model conditions (0.5М H₂SO₄ + 1М С₂Н₅ОН) is higher than that for analogous catalyst on XC 72 carbon and equals to 70 mA/mg_cat (E = 0.4 V).

The effect of the structure and the specific surface area of carbon materials, contained in positive electrodes, on the peculiarities of cycling of lithium-sulfur cells (the depth of electrochemical reduction of sulfur and lithium polysulfides, the changes in capacity and Coulomb efficiency of cycling) was studied.

A various features of the electrochemical behavior of number superfine carbon materials in electrolyte based on an ionic liquid 1-methyl-3-butilimidazolium tetrafluorineborate (1Me3BuImBF4) were determined by voltammetry and impedance methods. A comparative analysis of the effect of the type and nature of the electrolyte material on the main electrochemical characteristics of carbon electrodes which may be used in supercapacitors was done.

A kinetics of formic acid anodic oxidation at electrodes consisting from composites of platinum and palladium with polyelectrolytes is studied. Various polyelectrolytes studied have different functional groups. The composites were prepared via ionic exchange, and were supported at single walled carbon nanotubes. The following polyelectrolytes were studied: polydiallyldimethylammonium chloride (PDDA), polyethylene imine (PEI), polystirene sulfonic acid (PSS) and polyacrylic acid (PAA).

A kinetics of formic acid anodic oxidation at electrodes consisting from composites of palladium with polyaniline is studied. It was found that the contact of palladium with polyaniline does not result in the electrocatalytic activity enhancement, that differs such composites from composites of palladium with polyelectrolytes.

The use of heat of low-temperature sources dissipated into the environment for the production of useful energy is an urgent scientific and technical task. The article discusses the electrochemical principle of collecting the heat of low potential sources (temperature less than 100°C) and converting it into electricity using a thermoelectrochemical cell based on complex salts of potassium ferri/ferrocyanide redox electrolyte.