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Doping of carbon nanostructures with heteroatoms, such as boron or nitrogen, is one of the most effective ways to change their properties to make them suitable for various applications. Carbon nano-onions (CNOs) doped with boron (B-CNOs) were prepared by annealing (1650 °C) nanodiamond particles (NDs) under an inert He atmosphere in the presence of B. Their physicochemical properties were measured using transmission (TEM) and scanning (SEM) electron microscopy, X-ray photoelectron spectroscopy (XPS), B and B solid-state magic-angle spinning (MAS) NMR spectroscopy, X-ray powder diffraction (XRD), Raman spectroscopy, porosimetry, and differential-thermogravimetric analyses (TGA-DTG). These properties were systematically discussed for the undoped and B-doped CNO samples. The amount of substitutional B in the CNO samples varied from 0.76 to 3.21 at. %. The TEM, XRD, and Raman analyses revealed that the increased amount of B doping resulted in decreased interlayer spacing and polygonization of the structures, which in turn led to their unusual physicochemical properties. All synthesized materials were tested as electrodes for electrochemical capacitors. The B-CNOs with low concentration of doping agent exhibited higher reversible capacitances, mainly owing to the formation of hydrophilic polygonal nanostructures and higher porosity.

Heteroatom doping of carbon nanostructures is a convenient tool to control their physicochemical properties and to make them suitable for various applications. Carbon nano‐onions (CNOs) doped with nitrogen (N‐CNOs) have been prepared by annealing aminated‐nanodiamond particles (AM‐NDs) at different temperatures (1150, 1450 and 1650 °C) in an inert He atmosphere. Their physicochemical properties were compared with those of pristine CNOs obtained from non‐functionalized NDs under the same experimental conditions. The carbon nanostructures were characterized using transmission (TEM) and scanning (SEM) electron microscopy, X‐ray powder diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, porosimetry, and differential‐thermogravimetric analyses (TGA‐DTG). Their physicochemical properties are systematically discussed for undoped and for the nitrogen‐doped CNO samples. The results reveal that the surface morphology and the structure of undoped and nitrogen‐doped CNOs vary with the annealing temperature. All of these materials were electrochemically tested as electrode materials for enzyme‐free catalysis of hydrogen peroxide. The nitrogen‐doped carbon nanostructures have a higher catalytic activity than undoped nanostructures obtained under the same experimental conditions.

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The desirable properties of ionic liquids (ILs) enable their use in various branches of chemistry, through a wide range of applications, e. g. as organic electrolytes. In the present study, an efficient two‐step method was developed for the synthesis of long‐chain ionic liquids with alkyl derivatives of DABCO as cations and bis(trifluoromethane)sulfonimide as anions. ILs obtained with high yields (≥91 %) were solids with melting points that increased with the rise in the number of carbon atoms of the alkyl substituent in the bicyclic cation. The structure of the compounds was confirmed by spectroscopic methods and elemental analysis. All compounds were soluble in the main solvents except water and hexane. The solubility in organic solvents such as acetonitrile allowed the use of synthesized ILs in electrochemical capacitors. Electrochemical tests revealed that the ILs enhanced the conductivity of organic electrolytes. This phenomenon improved the cyclability and reduced the internal resistance of the electrochemical capacitors.

Carbon materials are commonly used catalyst supports in various types of fuel cells. Due to the possibility of designing their properties, they seem to be attractive and functional additives. In...

The borohydride electrooxidation process is complex. Technological application of carbon materials is manifested not only in their use as a catalyst support, but also as a physical trap for hydrogen generated during the parasitic hydrolysis.