ИСТИНА

Nitrogen-doped carbon nanotubes (N-CNTs) can be used as supports for catalysts, electrode materials for batteries and supercapacitors, adsorbents and components of different composite materials. One of the main challenges of the wide practical use of N-CNTs is their low density. It can be overcome using spark plasma sintering (SPS) – a technique allowing the production of compact materials of different shapes under high pressure and temperatures reached by passing of pulsed electrical current through the sample. In the present work N-CNTs were synthesised by pyrolytic decomposition of acetonitrile in the tube quartz reactor at 750 oC in the nitrogen flow in the presence of Co/Mo-MgO catalyst. The products have been investigated by thermal analysis, SEM, HRTEM, Raman spectroscopy, X-Rays diffraction and low temperature nitrogen sorbtometry as well as physical properties characterisation. The determination of the heat of combustion was performed on e2k isothermal bomb calorimeter. On the other hand, the change in internal energy can be determined by the first law of thermodynamics: ΔU = Q + A. This approach allows to estimate the change of the internal energy ΔU of the system and provides the ability to measure the energy of the formed bonds between the N-CNTs. Based on this results, the conclusions about the formation of new bonds between individual tubes and proposed a model of formation of 3D-frames were done.