Novel BN hollow microspheres with open mouths - Facile synthesis, growth mechanism, resonant Raman scattering effect, and cathodoluminescence performance

摘要

Novel BN hollow microspheres have been successfully fabricated by a facile chemical vapour reaction approach using ammonia-borane as a precursor. The morphology and structure of the as-synthesized products are characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), as well as electron energy loss spectroscopy (EELS). The hollow microspheres have open mouths and are 0.5-6 μm in diameter. The walls of the hollow spheres with thicknesses ranging from 200 to 800 nm are composed of poorly crystallized BN. The growth mechanism of the hollow microspheres is investigated and a growth model is proposed. The BN hollow spheres show pronounced resonant Raman scattering character under illumination of a 457.9 nm laser line, which implies a potential photothermal effect. The hollow microspheres also exhibit intense cathodoluminescence emissions in the region of 200-400 nm, indicating that they could be potentially used as compact ultraviolet laser emitters. Moreover, the unique open-mouth feature, in combination with the superior thermal and chemical stability of BN, makes the BN hollow microspheres potential candidates as microreactors for investigations of high-temperature space-confined chemical reactions. Novel BN hollow microspheres with open mouths have been fabricated. The unique open-mouth feature makes them potential candidates as microreactors. They show excellent cathodoluminescence performance in the region of 200-400 nm and could be used as compact ultraviolet laser emitters. Moreover, they exhibit an unexpectedRaman scattering effect.