Carbon doping

Chemical erosion can be suppressed by doping with substitutional elements such as boron. This is demonstrated in Fig. 14 [47] which shows data for undoped pyrolitic graphite and several grades of boron doped graphite. The mechanism responsible for this suppression may include the reduced chemical activity of the boronized material, as demonstrated by the increased oxidation resistance of B doped carbons [48] or the suppressed diffusion caused by the interstitial trapping at boron sites. 

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. 

The N-doped carbons with a nanotube backbone combine a moderate presence of micropores with the extraordinary effect of nitrogen that gives pseudocapacitance phenomena. The capacitance of the PAN/CNts composite (ca. 100 F/g) definitively exceeds the capacitance of the single components (5-20 F/g). The nitrogen functionalities, with electron donor properties, incorporated into the graphene rings have a great importance in the exceptional capacitance behavior. 

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. 

Figure 4. Particle size distributions for the original and ground B-doped carbon from WUT.

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... 

Figure 1. N2 adsorption (filled) and desorption (open symbols) isotherms for a) pure and Fe-modified SBA-15 and their N-doped carbon replicas b) pure and Fe-modified MLV-0.75 and their N-doped replicas (for clarity, the relevant isotherms are shifted up by 200 or 600 cm3g 1). Pore size distributions calculated from the desorption isotherms with the modified BJH method for c) pure and Fe-modified SBA-15 and CMK-3 carbons d) pure and Fe-modified MLV-0.75 and OCM carbons.

D.L. Carroll, X. Blase, J.C. Charlier, P. Redlich, P.M. Ajayan, S. Roth, and M. Ruhle, Effects of nanodomain formation on the electronic structure of doped carbon nanotubes. Phys. Rev. Lett. 81, 2332-2335 (1998). 

Chen, P., X. Wu, J. Lin, K.L. Tan, High H2 uptake by alkali-doped carbon nanotubes under ambient pressure and moderate temperatures. Science (Washington, DC) 285(5424), 91-93,... 

Yang, R.T., Hydrogen storage by alkali-doped carbon nanotubes. Carbon 38(4), 623-626, 2000. 

Liu J, Czerw R, Carroll DL (2005a) Large-scale synthesis of highly aligned nitrogen doped carbon nanotubes by injection chemical vapor deposition methods. Journal of Materials Research 20 538-543. 

Misra A, Tyagi PK, Singh MK, Misra DS (2006) FTIR studies of nitrogen doped carbon nanotubes. Diamond and Related Materials 15 385-388. 

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. 

Mechanical properties of doped carbon nanotubes-polymer composites... 

Y. Zhao, J. Wei, R. Vajtai, P. M. Ajayan, E. V. Barrera, Iodine doped carbon nanotube cables exceeding specific electrical conductivity of metals, Scientific Reports 1 83, 2011. 

J. D. Wiggins-Camacho, K. J. Stevenson, Effect of nitrogen concentration on capacitance, density of states, electronic conductivity, and morphology of N-doped carbon nanotube electrodes,/. Phys. Chem. C, vol. 113, p.19082-19090, 2009. 

R. Czerw, M. Terrones, J.-C. Charlier, X. Blase, B. Foley, R. Kamalakaran, N. Grobert, H. Terrones, D. Tekleab, P. M. Ajayan, W. Blau, M. Ru2hle, D. L. Carroll, Identification of electron donor states in N-doped carbon nanotubes, Nano Lett., vol. 1, pp. 457-460, 2001. 

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. 

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