Facilitating the Phase Transformations of Boron Nitride Nanoparticles at Mild Conditions by Solvothermal Hot-Press Route

Abstract

For preparing wurtzite and cubic boron nitride (wBN, cBN) under moderate conditions, here we developed a solvothermal hot-press method, by which the phase transformation of sp 3 -bonded BN in boron nitride (BN) nanoparticles was realized at quite low temperature and pressure. The results reveal that the transformation of aBN/rBN→cBN is highly dependent on the temperature, pressure and solvent promoting effect; and chlorobenzene seems to have a stronger effect on facilitating the phase transformation of sp 3 -bonded BN as compared to pyridine and aniline. Besides, the decrease in particle size and crystallinity as well as the existence of structural defects plays great roles on the phase transformations of sp 3 -bonded BN. On the basis of analyzing the experimental results, we proposed a simple model used for explaining the phase transformation process.