Structural and thermal properties of boron nitride nanoparticles

In the present study, our main motivation was to investigate the structural and thermal stability of BN nanoparticles (B1.0N0.9-NPs) produced by spray-pyrolysis (SP) of borazine at 1400 °C by thermogravimetric experiments and X-ray diffraction. We observed that B1.0N0.9-NPs are relatively stable in air below 850 °C in which only oxidation of the NP surface proceeded. Above 850 °C, the powders started to strongly react with air due to bulk oxidation. Under nitrogen, they appeared to be less stable than plate-like BN synthesized from borazine at 1400 °C through conventional pyrolysis. This is related to the low degree of crystallization of B1.0N0.9-NPs that clearly affects their stability. Using a post-pyrolysis treatment at 1400 °C, B1.0N0.9-NPs remained stable up to 1600 °C similarly to plate-like BN. However, above 1600 °C, a relatively fast weight loss occurred for B1.0N0.9-NPs, whereas plate-like BN remained stable up to 1800 °C. This indicated that their lower size also affects their high temperature thermal behavior.