Synthesis, structure, and properties of mesoporous B/C/N microspheres

Abstract

Reaction of low surface area carbon with a mixture of urea and boric acid at 930°C yields a composition close to BC₄N with a graphitic structure. BC₄N was characterized by electron energy loss spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, and X-ray diffraction. BC₄N is a porous ceramic with a surface area of 428 m²·g⁻¹, and shows a CO₂ uptake of 40 wt-%. The layered structure of BC₄N involves a random distribution of boron, carbon, and nitrogen atoms and shows high thermal stability up to 1000°C. A comparative analysis of the structure and properties of BC₄N and graphene using first-principles pseudopotential based density functional theoretical calculations is presented. The calculations predict it to be an insulator. The bulk modulus of BC₄N exhibits an interesting dependence on the ordering of boron and nitrogen on the graphene lattice.