Fabrication of boron- and nitrogen-doped carbon nanoparticles by stress from pyrolysis of borazine-containing arylacetylene

Abstract

Novel carbon nanoparticles doped with boron and nitrogen were prepared though curing and pyrolysis of the borazine-containing arylacetylene polymer (PBZA). PBZA was obtained by the condensation reaction between B,B′,B′′-trichloroborazine and an arylacetylene Grignard reagent, and borazine was introduced onto each structure unit of the polymers to satisfy the doping of boron and nitrogen. The PBZA would release amounts of heat and form a three-dimensional network structure after curing, which causes amounts of stress and produces many nano-cracks. The cured PBZA would form h-BCN (hexagonal BCN) crystals and nanocrystals after carbonization. The formation of carbon nanoparticles can be considered to consist of two stages. The first stage is that PBZA is cured and divided into many nano-regions by nano-cracks from the thermal stress produced by curing and pyrolysis. The second stage is that with the temperature increasing further, stress is produced by the formation of h-BCN and nanocrystalline graphite, which promotes the formation of nanosphere-like particles.