Zhen Yao

Preparation of SiO 2 nanowires by using carbon as reducing agent

SiO2 nanowires structures have been grown by a simple thermal evaporation method using C and SiO2 as the source materials at a relatively low. The as-synthesized products were characterized by scanning electron microscopy, electron energy-dispersive X-ray (EDX), X-ray powder diffraction (XRD), Raman spectroscopy (RS) and photoluminescence (PL). The products characterization indicated that the SiO2 nanowires with diameters ranging from 60nm to 120nm with a hexagonal strcture, with the length up to a few centimeters. The photoluminescence spectra of the grown products indicate excellent optical properties for the as-grown SiO2 nanowires.

Amorphous SiO 2 nanoparticles grown on the surface of the nanowires

SiO2 amorphous nanoparticles have been successfully synthesized on the surface of the SiO2 amorphous nanowires via a thermal evaporation method using SiO powders as the source agents. The as-synthesized products have been systematically studied by X-ray powder diffraction (XRD), Raman spectroscopy (RS), scanning electron microscope (SEM), electron energy-dispersive X-ray (EDX) and photoluminescence (PL). The results indicate that SiO2 amorphous nanoparticles grown on the amorphous nanowires at the temperatures of 1135 °C. Furthermore, The RT PL spectral results reveal the obtained composite structures have a stable and strong yellow-green emission range. The products are available for the applications in optoelectronic semiconductor devices with improving performances.

S-doped SiO 2 microsphere structure prepared by thermal evaporation

S-doped SiO2 microspheres have been successfully synthesized via the thermal evaporation method using S powders as the reducing agents. The as-synthesized products have been systematically studied by X-ray powder diffraction (XRD), Raman spectroscopy (RS), scanning electron microscope (SEM), electron energy-dispersive X-ray (EDX) and photoluminescence (PL). The results indicate that pure S-doped SiO2 microspheres were collected at the growth temperatures of 730 °C. Furthermore, The RT PL spectral results reveal the S-doped SiO2 microspheres have a stable and strong green emission band. The products are available for the applications in optoelectronic semiconductor devices with improving performances.

The structure and interaction mechanisms of C10H16@(13, 0)SWCNT under high pressure

The high-pressure deformation and polymerization of peapod structure (C10H16 filled into (13, 0) single-walled carbon nanotube) is studied by using density function theory. The guest–host interaction mechanism under pressure is analyzed by combining the van der Waals (vdW) potential with the electron localization function (ELF). Our studies show that the cross-section of the filled single-walled carbon nanotube changes from a circle into an ellipse shape, and then into a walnut shape with the transition pressures of 3 GPa and 10 GPa, respectively. The intertubular bonding of adjacent tubes occurs at 17 GPa, 30 GPa, 32 GPa, 82 GPa and 152 GPa. The attractive and repulsive guest–host interactions are exhibited for the pressures lower and higher than 10 GPa, respectively. Except for the ambient pressure structure, six stable high pressure structures, which can hold their structures when the pressure is released, are identified by combining the systematic binding energy with geometry optimization.

Preferable Orientations of Interacting C-60 Molecules inside Single Wall Boron Nitride Nanotubes

This work focuses on the preferable orientation analysis of the hybrid system where the C60 molecules are encapsulated inside the boron nitride nanotubes by using the two-molecule model. The low-energy state can be acquired in the contour map, which provides the visual information of the systematical van der Waals interaction potential for the C60 molecules adopting different orientations. Our results show that the C60 molecules exhibit the preferred pentagon and hexagon orientations with the tubes diameter smaller and larger than 13.55 A, respectively. The preferred two-bond orientation obtained in the single-molecule model is absent in this study, indicating that the intermolecular interaction of adjacent C60 molecules plays an important role in the orientational behaviors of this peapod structure.