Synthesis of high-purity boron nitride nanocrystal at low temperatures

High-purity nanocrystalline boron nitride has been successfully synthesized by a simple synthesis method using amorphous B powder and NaN3 as the reactants and anhydrous CH3CN as the solvent at 380 degrees C. Results from XRD, FT-IR, EELS, and BET absorption measurements suggest that the synthesized product can be indexed as pure hexagonal BN with lattice constants of a = 2.497 angstrom and c = 6.678 angstrom, and the specific surface area of product is 52.19 m(2)/g. The TEM images show the multiplex belt spherelike, fiberlike, sheetlike, and tubelike morphologies of the products. Here, the multiplex belt spherelike and sheetlike structures are reported for the first time. When the temperature of reaction and the solvent are controlled, BN products with particular morphologies can be selectively produced. The optical properties of the product are observed in the PL spectra, which shows that the as-prepared BN emits strong visible luminescence at 580 nm (lambda(ex) = 325 nm).