Growth and Optical Properties of Explosion Phase Boron Nitride Octahedron Crystals

Abstract

A low temperature and high pressure synthetic route assisted with ball milling has been established to prepare high quality orientated explosion phase boron nitride (E-BN) octahedron crystals using H 3 BO 3 , iron powders, NH 4 Cl, and Mg as starting materials. FSEM, TEM, HRTEM, SAED, XRD, Raman, FTIR, and XPS were employed for characterization of the morphology and structure of as-synthesized E-BN samples. The E-BN was identified as the face-centered cubic structure with a lattice parameter of 8.245 Å. The typical particle sizes were mainly in the range of 30−120 nm. A UV spectrum indicated that the product has an obvious absorption band (5.61 eV). Photoluminescence spectra revealed that it has a dominant ultraviolet emission peak at 383 nm. The possible chemical reactions as well as the proposed mechanism of the growth of E-BN octahedron crystals were also discussed.

Magnetic Fe3O4–FeB nanocomposites with promoted Cr(VI) removal performance

“…Where D is the crystallite size (nm), λ is the wavelength of the monochromatic X-ray beam (0.154056 nm), ω is the full width at half-maximum (FWHM) value of X-ray diffraction lines under consideration (see Fig. 1c), K is a constant (equal to 0.9), and θ is the half diffraction angle of 2θ (degree Figure 5b) [24][25][26]. The calculation of the peak area in core level spectra of Fe 2p gave a ratio of ferrous iron to total iron (Fe II /Fe total ) and ferric iron to total iron (Fe III /Fe total )( Table 2).…”

Solvent-free catalytic synthesis and optical properties of super-hard phase ultrafine carbon nitride nanowires with abundant surface active sites

“…[41][42][43] Meanwhile, NH 4 Cl was also dissociated into active vapor N* and H 2 and HCl (eqn (2)). [44][45][46] Then new generated chemically active C*, N* and H 2 reacted with catalyst Fe 2 O 3 and formed carbon-nitride-catalyst middle product [C*-N*-Fe*] liquid drop and H 2 O vapor (eqn (3), Fig. 6(a)).…”

“…6(a)). 44,47 According to the VLS growth mechanism, with the help of catalyst Fe, C 3 N 4 nanowires began to grow on the surface of [C*-N*-Fe*] when the C*and N* were supersaturated (eqn (4), Fig. 6(b)).…”

Growth mechanism and ultraviolet-visible property of novel thick-walled boron nitride nanostructures

“…B and N vacancies, dislocation, stacking defect), and even preparation method. 32,48,[57][58][59][60][61]…”