Low temperature synthesis via molten-salt method of r-BN nanoflakes, and their properties

Abstract

r-BN nanoflakes were synthesized using KBH4 and NH4Cl as the main raw material in a high-purity nitrogen atmosphere. The effects of salt and salt-free conditions and heating temperature on the synthesis of BN were studied. The molten-salt method was used to synthesize BN at 650 °C, which was 250 °C lower than the BN synthesis method without salt. Furthermore, at 1000 °C the prepared flake-like BN crystals showed good crystallinity, uniform morphology, a particle diameter of 200–300 nm, and a thickness of 40–70 nm. Moreover, the specific surface area of BN was 294.26 m2/g. In addition, the BN synthesized at 1100 °C had a large elastic modulus value and good oxidation resistance.