Fabrication and characterization of hexagonal boron nitride powder by spray drying and calcining–nitriding technology

Hexagonal boron nitride (hBN) powder was fabricated prepared by the spray drying and calcining–nitriding technology. The effects of nitrided temperature on the phases, morphology and particle size distribution of hBN powder, were investigated. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier transformed infrared spectrum, ultraviolet–visible (UV–vis) spectrum and photoluminescence (PL) spectrum. UV–vis spectrum revealed that the product had one obvious band gap (4.7 eV) and PL spectrum showed that it had a visible emission at 457 nm (λex=230 nm). FESEM image indicated that the particle size of the synthesized hBN was mainly in the range of 0.5–1.5 μm in diameter, and 50–150 nm in thickness. The high-energy ball-milling process following 900 °C calcining process was very helpful to obtain fully crystallized hBN at lower temperature.