S.R. Qi

SiC and its bicrystalline nanowires with uniform BN coatings

Uniformly BN-coated SiC nanowires have been synthesized within the framework of vapor–liquid–solid growth mechanism. Nanoscale Ni–C alloy covering graphite sheet was used as catalysts and the mixture of boron and silica was heated to simultaneously generate B2O2 and SiO gas-phase precursors. 2 to 4 nm BN layers were found to coat the overall surface of the inside of the SiC nanowires with the diameters ranging from several nm to 80 nm. The bicrystalline structure of SiC nanowires with BN coating were also observed and had a [311] growth axis at least. The structures and possible coating mechanism have been studied by high-resolution transmission electron microscopy.

Synthesis of BN nanobamboos and nanotubes from barium metaborate

Abstract Nanobamboo and nanotube structures of BN have been controllably synthesized by reaction of barium metaborate with ammonia. The gallium addition plays an important role in the formation of nanotubes. The experimental results indicate that, without the gallium additive, the reaction results in the growth of nanobamboo structure. Gallium addition, probably as a catalyst within the framework of vapor–liquid–solid growth, promotes the growth of nanotubes. High-solution transmission electron microscopy research indicates that rhombohedral stacking order is the dominant atomic arrangement for BN nanobamboos; whereas hexagonal stacking is the dominant arrangement for BN nanotubes.

Characterization and photoluminescence properties of aluminum borate nanorods doped with Eu

Aluminum borate (Al18B4O33) nanorods doped with Eu3+ and Eu2+ were synthesized via a simple calcination method. Both nanorods are of straight morphology and smooth surface, with the average diameter of ∼80nm. The structural and compositional characteristics have been investigated by x-ray diffraction, infrared spectra, and various microscopy techniques. A possible growth mechanism was proposed for the synthesis of the doped Al18B4O33 nanorods. Photoluminescence measurements indicate that Al18B4O33:Eu3+ nanorods exhibit emission peaks at 590, 595, 612, and 617nm, and Al18B4O33:Eu2+ nanorods display a broad green emission band centered at ∼540nm.

Facile nanocoating method: From B-doped to BN-coated one-dimensional nanostructures

B-doped MgO nanowires were synthesized through impurity-assisted physical evaporation of a mixture of B and MgO with a small amount of Ga2O3. The B content in the mixture affectsthe morphology of MgO nanowires. B-doped MgO nanotubes and cubes were formed when B-rich mixtures were utilized. Ammonothermal treatment of as-synthesized B-doped products resulted in the formation of uniform BN coatings adherent to nanowire and nanotube surfaces. Thus a facile BN coating method was developed. Finally the growth mechanism of the present BN-coated one-dimensional nanostructures was proposed.