Amorphous carbon nanofibers

Barranco, V. et al. Amorphous carbon nanofibers and their activated carbon nanofibers as supercapacitor electrodes. J. Phys. Chem. C. 2010,114(22), 10302-10307. 

Cheng, K. K. T.C. Hsu, and L.H. Kao, A microscopic view of chemically activated amorphous carbon nanofibers prepared from core/sheath melt-spiiming of phenol formaldehyde-based polymer blends. J. Mater. Sci. 2011,46(11), 3914-3922. 

Barranco, V. et al. (2010). Amorphous Carbon Nanofibers and Their Activated Carbon Nanofibers as Supercapacitor Electrodes. 4,... 

As reported elsewhere [22], similar to those found on other catalysts, the forms of carbon materials deposited on Fe-loading zeolite molecular sieves are carbon nanotube, carbon nanofiber and amorphous carbon. One obvious phenomenon of the carbon nanotubes formed on Fe/NaY or Fe/SiHMS catalysts is that almost all tips of these tubes are open, indicating the interaction between catalyst particles and supports is strong [23]. On the other hand, the optimal formation time of carbon nanotubes on Fe/SiHMS is longer than that on Fe/NaY. However, the size of carbon nanotubes is easily adjusted and the growth direction of carbon nanotubes on the former is more oriented than on the latter. 

Keywords Single-walled nanotubes Multi-walled nanotubes Nanofibers Amorphous carbon Pt nanoclusters Fuel cell. 

Pt superfine clusters on conductive supports are effective catalysts of redox reactions proceeding in fuel cells. High specific surface, support conductivity, high dispersity (nanosizes of Pt clusters) and their strong fixation on a surface are necessary criterions of preparation of the effective catalyst. From these points of view CNM for example single- (SWNT) and multi-walled (MWNT) nanotubes, nanofibers (CNF) and x-ray amorphous carbon (AC) can be a successful supports of Pt clusters. 

In spite of high surface area (nearly 300-500 m2/g), oxidation of the samples in air begins at temperatures higher than 500°C (Fig. 5). This indicates absence of amorphous carbon, which usually bums in air at 350-450°C. However, structure of the nanofibers obtained remains unclear. 

Fig. 7.1 TEM micrographs showing the microstructural arrangement of the graphene pianes in (A) carbon nanotubes paraiiel to the tube axis and in (B) carbon nanofibers fishbone arrangement aiong the fiber axis. The thin amorphous carbon iayer visuaiized on the topmost iayers of the materiais is attributed to the iow-temperature decomposition of the starting carbon source...

As compared to mesoporous oxide nanofibers, much lesser attention has been paid to their mesoporous amorphous carbon analogues. However, mesoporous carbon exhibits superior resistance to acids and bases, excellent heat resistance, as well as high intrinsic electric conductivity. Potential applications for hybrid membranes consisting of mesoporous carbon within hard templates include size-selective electrosorption, electrosynthesis of nanostructures, catalysis, separation and storage. The first reported procedure for the synthesis of mesoporous carbon nanofibers involved the preparation of... 

Abbreviations aC, amorphous carbon CNTs, carbon nanotubes CNFs, carbon nanofibers CVD, chemical v or deposition CSs, carbon spheres FcH, ferrocene HCSs, hollow carbon spheres NPs, nanoparticles. 

The conductivity of the electrode is cmcial factor for fast-response actuators. Unfortunately without improvements in the electrode conductivity, the porous carbons are not able to work at excitation frequencies higher than 1 Hz (Palmre et al. 2012 Sugino et al. 2009). One way is to tune the properties of carbon by choosing suitable precursors and synthesis conditions however, as discussed above, another approach to enhance the electrical conductivity of carbon-based electrodes is to combine amorphous carbon with carbon having higher electrical conductivity, such as CNTs with CDC, CNTs, or vapor-grown carbon nanofibers with activated carbon nanofibers or with carbon black. 

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