A New Approach for Synthesizing Ultrathin Hexagonal Boron Nitride Nanoparticles Through Two-step Thermal Treatment

A method for obtaining hexagonal boron nitride (h-BN) nanoparticles 2–10 nm in size with a crystallinity of up to 99% has been developed. The method is based on two-stage thermal treatment at temperatures of 600 and 1000°C using boric acid, urea, nitrogen and hydrogen. X-ray phase analysis, high-resolution transmission electron microscopy, electron diffraction in the selected area, and analysis of electron density maps confirmed the hexagonal structure of h-BN with an interplane distance of 3.3 Å, a narrow size distribution, and a uniform distribution of elements in the material. The proposed approach eliminates the use of toxic ammonia, is energy efficient and suitable for industrial scaling. The resulting nanoparticles can be used in tribological coatings and lubricants.