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Flexible graphite can be stamped into gas channels for proton exchange membrane fuel cells attributing to its good conductivity, corrosion resistance and flexibility. However, the electrical resistance of the bipolar plate consisting of a coated metal foil and the stamped flexible graphite flowfield plate should be investigated, for the internal resistance would affect the output power of the fuel...
The pore surface of mesoporous silica SBA-15 was coated with 2,3-dihydroxynaphthalene (DN) through a dehydration reaction between the surface silanol groups in SBA-15 and the hydroxyl groups of the DN molecules. By the carbonization of DN in the SBA-15 pores, the pore surface was uniformly covered with an extremely thin carbon layer, which comprised only 1–2 graphene sheets. The resulting carbon-coated...
Carbon encapsulated SnO 2 composites were prepared by a thermal evaporation and decomposition of malic acid (C 4 H 6 O 5 ) at low temperature to demonstrate their potential use for application in lithium ion batteries. The solution-based chemical approach was effective for coating amorphous C layers on the surface of SnO 2 nanopowders without significant oxygen...
Nitrogen-containing carbon nanotubes (NCNT) were grown from acetonitrile, pyridine or N,N-dimethylformamide over a supported Fe-, Co- or Ni catalyst in the temperature range 823–1123K. The physico-chemical properties of the obtained NCNT, such as the C/N ratio or the nitrogen type, were related to the synthesis parameters. It was found that the C/N ratio increased with increasing temperature which...
An ultralong (1.0mm) aligned carbon nanotube (ACNT) electrode was fabricated by a cut/paste method. The electrode retains the intrinsic properties, including robust mechanical property, high surface area, and regular pore structure, of individual nanotubes. Electrochemical properties of the ACNT electrode in an ionic liquid (IL) electrolyte were studied by cyclic voltammetry, galvanostatic charge/discharge,...
Nanoporous activated carbon fibers (ACFs) feature 3D disordered networks of nanographite domains that consist of stacks of 3–4 nanographene sheets each. At the peripheries of the nanographene sheets, the localized spins of a nonbonding edge state are created. The magnetic properties of the edge-state spins in ACFs are investigated in relation to the interaction with acid molecules adsorbed in the...
In order to improve the oxidation behavior of carbon/carbon silicide carbide composites prepared by liquid silicon infiltration of carbon/carbon porous preforms, a multilayer coating of dense SiC alternated with porous Si–Mo was prepared by chemical vapor deposition combined with slurry painting. Oxidation test showed that weight loss of the coated sample was only 0.25% after 150h oxidation in air...
A cobalt-polymer-MWCNT composite has been developed as an electrocatalyst for the oxygen reduction reaction (ORR) in PEMFC. The suitability of this electrocatalyst for the ORR in direct methanol fuel cells and direct ethanol fuel cells has been examined by taking Pt–Ru/MWCNT and Pt–Sn/MWCNT, respectively as an anode electrocatalysts. The study results in improved power densities for hydrogen, methanol...
Long, oriented vapor-grown carbon fibers with high purity were synthesized from coal pitch by chemical vapor deposition using ferrocene as catalyst precursor and hydrogen as carrier gas. Field emission scanning electron microscopy, energy dispersive spectroscopy, high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and thermalgravimetric analysis were employed to...
A liquid–solid synthesis method to prepare high quality bulk samples of MC 6 binary graphite intercalation compounds (with M=Ca, Ba and Eu) is described. Liquid Li–M alloys are used to synthesize such compounds for two reasons: first, lithium spreads apart the graphene sheets and second, it allows the intercalation reactions to be carried out at temperatures sufficiently low to avoid the formation...
A simple method for preparing the mesophase-pitch-based carbon foams at low pressures through prolonging the soaking time in the preparation process of the mesophase pitch was disclosed. The physical properties, morphologies and the crystal structure of the as-obtained foams were investigated. Bulk density of the resultant carbon foams cover a range 0.514–0.624g/cm 3 , under the preparation...
It is known that single-walled carbon nanotubes (SWCNTs) can be functionalized by fluorine gas. Here, we report neutralized fluorine radical detection using a matted sheet of SWCNTs, prepared by alternating current dielectrophoresis. Upon exposure to neutralized radicals containing fluorine atoms in a plasma, as model analytes, the conductance of the SWCNT matt showed fast modulation. The transduction...
A new approach is reported to cut conventionally long (>10μm) and entangled carbon nanotubes (CNTs) to those with short lengths (∼300nm) and excellent dispersion in water and ethanol. This was achieved by depositing Fe 2 O 3 nanoparticles on CNTs first and then inducing a chemical reaction between them at a temperature of 850°C. The consumption of carbon during the reduction of...
In this work, a numerical study is proposed to investigate and predict the thermal performance of graphite foams infiltrated with phase change materials, PCMs, for space and terrestrial energy storage systems. The numerical model is based on a volume averaging technique while a finite volume method has been used to discretize the heat diffusion equation. A line-by-line solver based on tri-diagonal...
Hydrogen sorption properties were investigated for selected mixtures of MgH 2 and carbon materials, including graphite, activated carbon, multi-walled carbon nanotubes (MWCNTs), carbon nanofibres (CNFs) and activated carbon fibres. The introduction of such carbon materials decreases the decomposition temperature of MgH 2 . The best results were achieved in the mixtures involving CNFs...
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