Structure of nanoporous carbon produced from boron carbide

The structure of nanoporous carbon produced by chlorination of powdered boron carbide at 600, 800, 1000, 1300, 1500, and 1800 °C has been studied by scanning electron microscopy, X-ray diffraction analysis, helium pycnometry, and low-temperature adsorption of nitrogen. On the basis of the results obtained, suggestions are made concerning the type of organization of the nanoporous structure of these materials. The evolution of the structure of nanoporous carbon is analyzed in relation to the synthesis temperature of nanoporous carbon. It is shown that, as the chlorination temperature increases, the structure of nanoporous carbon becomes more perfect: it changes from paracrystalline to turbostratic. The specific surface area decreases from 2200 to 36 m2/g, the volume of micropores decreases from 0.93 to 0.01 cm3/g, and that of mesopores first increases from 0.15 cm3/g (600 °C) to 0.57 cm3/g (1000 °C) and then decreases to 0.19 cm3/g (1800 °C). The total pore volume decreases from 1.08 to 0.20 cm3/g.