Synthesis of ultraviolet luminescent turbostratic boron nitride powders via a novel low-temperature, low-cost, and high-yield chemical route

A novel chemical route has been established for the synthesis of ultraviolet luminescent turbostratic boron nitride (t-BN) powders, by the reaction of NH4BF4 with NaNH2 at 320 degrees C for 10 h, and the yield is as high Lis 90%. The synthesized brown-yellow samples were characterized by XRD, XPS, FT-IR, SAED, and HRTEM, which matched with t-BN. The electronic and optical properties of the product were investigated by PL and UV absorption. UV spectra revealed that the product has two obvious band gaps (similar to 5.8 and 4.6 eV) and PL spectra showed that it has an ultraviolet emission at 337 nm (lambda(ex) = 260 nm). SEM image indicated that the particle size of the synthesized t-BN is mainly in the range of 1-10 mu m. The renascent BF3 and Na3N intermediates are believed to be responsible for the growth of t-BN under mild conditions. (c) 2005 Elsevier Inc. All rights reserved.