Boron-doped carbon

This contribution Is concerned with the magnetic and Mossbauer characterization of (a) Fe/zeollte (mordenlte) systems, and that of (b) Fe and/or Ru on boron-doped carbon substrates. Some correlations between the characterization and CO hydrogenation parameters will be pointed out. Because of limitations of space, we shall present salient features of these Investigations. At the outset. It would be befitting to present a succinct background on the basic principles of magnetic and Mossbauer characterization. 

In the third paper, M. Walkowiak et al. report on findings of Central laboratory of batteries and Cells (CLAiO) in Poland, as related to the electrochemical performance of spherodized purified natural graphite and boron-doped carbons in lithium-ion batteries. While it is noteworthy that... 

As the end-user in the NATO SfP project Carbons as materials for the electrochemical storage of energy Central Laboratory of Batteries and Cells does research and development works on the application of novel carbonaceous materials to the Li-ion technology. The general idea of these works is to build prototypes of cylindrical Li-ion cells on the basis of materials produced in the cooperating laboratories. The aim of this paper is to examine the applicability of selected commercial and non-commercial carbon materials (with special attention devoted to boron-doped carbons) to the construction of a practical cylindrical Li-ion cells. 

Boron-containing carbons synthesized by co-pyrolysis of coal-tar pitch with pyridine-borane complex (series 25Bn) have already been considered as hosts for lithium insertion [4], Unlike the commercial graphites described above, the boron-doped carbon 25B2 (WUT) as received was not suitable for direct use in the cylindrical cell due to very large and hard particles. This feature makes the coating process very difficult. 

Commercial and non-commercial carbons were tested for their applicability as anode of lithium-ion battery. It was found that Superior Graphite Co s materials are characterized both by high reversible capacities and low irreversible capacities and thus can be regarded as good candidates for practical full cells. Cylindrical AA-size Li-ion cells manufactured using laboratory techniques on the basis of SL-20 anode had initial capacities over 500 mAh (volumetric energy density ca. 240 Wh/dm3). Boron-doped carbon... 

Xu JF, Xiao M, Czerw R, Carroll DL (2004) Optical limiting and enhanced optical nonlinearity in boron-doped carbon nanotubes. Chemical Physics Letters 389 247-250. 

W. Han, Y. Bando, K. Kurashima, T. Sato, Boron-doped carbon nanotubes prepared through a substitution reaction, Chem. Phys. Lett., vol. 299, pp. 368-373,1999. 

B. Wei, R. Spolenak, P. Kohler-Redlich, M. Riihie, E. Arzt, Electrical transport in pure and boron-doped carbon nanotubes, Appl. Phys. Lett., voi. 74, p. 3149-3151,1999. 

Applications of CNTs based on their electrical properties strongly depend on the diameter and helicity as well as parity.2 3 Doping of CNTs by boron and nitrogen renders them p-type and retype, respectively. MWNTs and SWNTs doped with nitrogen 4 17 and boron"1 9 have been reported. Boron-doped carbon nanotubes appear to exhibit enhanced electron field emission due to the presence of the boron atom at the nanotube edges.20 2 N-doped CNTs show retype behavior regardless of tube chirality.22... 

In this paper, to meet the different requirements in self-healing CMCs, typical boron carbide and boron doped carbon was prepared by CVD ftom BCla-CH -Ha-Ar and BClj-CaH -Ha-Ar mixture, respectively. Microstructures, phases and chemical bonding characters of the deposits were systematically analyzed and the relationship between microstmctures and compositions was discussed. 

It has been shown that substituted boron atoms in the carbon lattice can accelerate the graphitization and suppress the oxidation of carbon materials [149-152]. Furtha-, electromagnetic properties of graphite are reported to be strongly affected by a small amount of substituted boron [153]. An example of application is the use of boron-doped carbon fibers, BCx, as a reinforcement of C-C composites in the aerospace industry, as an alternative to C-C structural materials that oxidizes at temperatures in excess of673 K [154—155]. 

Fig. 29. a LDOS of carbon nanotubes and boron-doped carbon nanotubes [177]. It is interesting to note the intrinsic metallic behaviour of the doped tubes. A possible explanation is based upon the existence of BC3 islands within the carbon hexagonal network (courtesy of P.M. Ajayan). b Microwave conductivity measurements of B-doped nanotubes obtained by arcing a mixture of h-BN and graphite in an He atmosphere exhibiting the unusual metallic behaviour [19]... 

Wang RX, Zhang DJ, Zhang YM, Liu CB et al. (2006) Boron-doped carbon nanotubes serving as a novel chemical sensor for formaldehyde. J. Phys. Chem. B 110 18267-18271. 

Zhang, Y., Zhang, D. and Liu, C. (2006), Novel chemical sensor for cyanides boron-doped carbon nanotubes ,/ouraa/ of Physical Chemistry B, 110,4671-4. 

---