Modern process methods and approaches to production of useful electrode materials make it possible to design alternative power sources, in particular, fuel cells with high specific characteristics. ...Owing to their unique properties, carbon nanotubes and porous silicon are the most promising materials for developing micropower current sources. Substrates based on porous silicon have high corrosion and mechanical resistance, and they also feature a large pore surface area. Hence, the search for the best composition of matrix carriers with a large active surface and modifier metals with their minimum load is becoming an urgent process problem in power and electronic engineering. The use of metal nanoparticles in a catalyst can increase the catalytic activity in electrochemical reactions occurring in fuel cells and their corrosion resistance. Investigations into electrochemical oxidation of hydrogen and formic acid in fuel cells seem to be the most important for practice due to a wide application range of these types of fuels. This work deals with the formation of nanocomposite electrodes with nanoparticles of platinum group metals for fuel cells to be used as self-contained micropower current sources in electronic engineering. A process is described for forming effective electrode materials based on nanotubes with nanoparticles of platinum (Pt) and palladium (Pd) for low-temperature self-contained power sources. Parameters of nanocomposite electrodes in matrix-carriers are investigated by the methods of atomic-force, high-resolution transmission electron microscopy. The results from tests of formic acid–air and hydrogen–air fuel cell models are presented. The optimal loading of platinum group metals and dimensions of electrode nanocomposites giving maximum specific power and current density are found.
Thomson scattering of the core edge and divertor plasma regions of a tokamak with reactor technologies is discussed. The rationale and choice of technical solutions are given, the composition of the ...Thomson scattering diagnostic complex is discussed, as well as an estimate of the accuracy of measuring both electron temperature and density. Particular attention is paid to ensuring the functionality of the proposed diagnostics in the reactor mode of the tokamak operation and the results of testing diagnostic equipment in the experiments on Globus-M2 tokamak.
Two alternative approaches to measuring the depth of nanoholes (nanopits) formed in metallic aluminum in the process of its high-voltage anodizing are proposed. The first approach consists of the ...electron microscopic study of a metallic layer section formed by cutting ions with the use of a sputtered protective platinum layer with immediate observation of an array of nanopits. The second (indirect) method consists of manufacturing copper replicas from a metallic aluminum layer with the further electrochemical measurement of the overall surface area of the copper electrode and the calculation of the height of the copper nanobristles. It is shown that both approaches lead to the same results.
In this work the effective electrode materials for autonomous energy sources based on porous silicon modified by platinum nanoparticles have been obtained. The functional characteristics of the ...electrodes have been studied by transmission electron microscopy and voltammetry methods. The electrode materials based on porous silicon had demonstrated high catalytic activity in fuel cells with hydrogen oxidation.
In this work the electrode materials on combined polymer-carbon matrix-supports modified by bimetal platinum-ruthenium nanoparticles have been formed. The functional characteristics of the electrodes ...have been studied by atomic force microscopy, scanning electron microscopy and voltammetry methods. The catalytic activity of the synthesized composites in the methanol oxidation reaction had been studied.
In this work the electrode materials on Nafion modified by bimetal platinum-ruthenium nanoparticles have been formed. The functional characteristics of the electrodes have been studied by atomic ...force microscopy, scanning electron microscopy and voltammetry methods. The catalytic activity of the synthesized composites in the methanol oxidation reaction at different temperatures had been investigated.
Composite material for optical oxygen sensor Antropov, A P; Ragutkin, A V; Melnikov, P V ...
IOP conference series. Materials Science and Engineering,
01/2018, Letnik:
289, Številka:
1
Journal Article
Recenzirano
Odprti dostop
A new composite material for use in optical molecular oxygen sensors is proposed. The absence of pores on the surface of the material avoids microbiological fouling and concomitant deterioration of ...the characteristics with time, and the presence of the mesoporous phase results in a linear calibration and acceptable response times, even for layers that are significant in thickness.
Energy-efficient bimetallic electrode nanocomposite materials for membrane electrode assemblies for alkaline water electrolysis (AWE) have been developed. The nanomaterials are studied by atomic ...force microscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The energy efficiency of hydrogen and oxygen generation is estimated on a test stand for AWE. The optimal load of platinum metals and the temperature conditions of the operation of the membrane electrode assemblies are determined to reach a higher current density, a longer lifetime of the alkaline water electrolyzer, and the lowest hydrogen and oxygen overpotential. This work demonstrated that membrane electrode assemblies for AWE can be made of porous nickel electrodes modified with platinum–nickel and palladium–nickel bimetallic nanoparticles.
The specific features of dependences of the magnetic anisotropy constants on the thickness of yttrium iron garnet films prepared by pulsed laser deposition were studied. Films with thicknesses of ...96–333 nm were produced by pulsed laser evaporation of the target material and deposition onto gadolinium-gallium-garnet substrates with the (111) orientation. The results of an investigation into static magnetic properties showed that the saturation magnetization decreases as the films get thinner. The high-frequency properties were studied by ferromagnetic resonance (FMR). The uniaxial and cubic anisotropy fields and the relaxation parameter were determined by analyzing the angular dependences of the resonance field and the FMR line width. It was found that as the thickness decreases, the strength of the uniaxial anisotropy field increases monotonically, while the cubic anisotropy field decreases and reverses its sign.
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