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Wang X.,Hunan University | Zou B.,Hunan University | Zou B.,Micro nano Technology Center | Zhang Q.,Hunan University | And 3 more authors.
Journal of Alloys and Compounds | Year: 2011

CdS and ZnS nanostructures with complex urchinlike morphology were synthesized by a facile solvothermal approach in a mixed solvent made of ethylenediamine, ethanolamine and distilled water. No extra capping agent was used in the process. The structure, morphologies and optical properties of these nanostructures were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The as-synthesized urchinlike architectures were composed of nanorods with wurtzite structure. The preferred growth direction of nanorods was found to be the [0 0 1 direction. The PL spectrum of CdS nanostructures exhibited a highly intense red emission band centered at about 706 nm. On the basis of the experimental results, a possible growth process has been discussed for the formation of the CdS and ZnS urchinlike structures. © 2011 Elsevier B.V.


Wang X.,Hunan University | Zhang Q.,Hunan University | Zou B.,Hunan University | Zou B.,Micro nano Technology Center | And 2 more authors.
Applied Surface Science | Year: 2011

Mn-doped ZnS sea urchin-like architectures were fabricated by a one-pot solvothermal route in a ternary solution made of ethylenediamine, ethanolamine and distilled water. The as-prepared products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence spectra (PL). It was demonstrated that the as-prepared sea urchin-like architectures with diameter of 0.5-1.5 μm were composed of nanorods, possessing a wurtzite structures. The preferred growth orientation of nanorods was found to be the [0 0 2] direction. The PL spectra of the Mn-doped ZnS sea urchin-like architectures show a strong orange emission at 587 nm, indicating the successful doping of Mn2+ ions into ZnS host. Ethanolamine played the role of oriented-assembly agent in the formation of sea urchin-like architectures. A possible growth mechanism was proposed to explain the formation of sea urchin-like architectures. © 2011 Elsevier B.V. All rights reserved.


Wang X.,Hunan University | Zhang Q.,Hunan University | Wan Q.,Hunan University | Dai G.,Micro nano Technology Center | And 3 more authors.
Journal of Physical Chemistry C | Year: 2011

Controllable ZnO architectures with different morphologies were synthesized via an ethanolamine-assisted one-pot hydrothermal method. By adjusting reaction conditions such as the molar ratio between Zn(OAc)2 and NaOH and the volume ratio of the ethanolamine/water, the flowerlike, spindlelike, swordlike, and umbellarlike ZnO architectures of the hexagonal phase have been obtained. The as-prepared ZnO products were characterized by FE-SEM, TEM, XRD, BET, PL, and Raman spectroscopy. The ethanolamine significantly influenced the morphology of ZnO products, which is related to the competitive adsorption between ethanolamine and [Zn(OH)4]2- to ZnO nuclei. Their PL spectra depend on their morphologies and phase structures. The morphology-dependent photocatalytic performances in the degradation of methylene blue under UV illumination were observed, in which the flowerlike ZnO structures exhibit highest activity for their most irregular surface Zn sites. © 2011 American Chemical Society.


Dai G.,Central South University | Chen Y.,Central South University | Wan Q.,Hunan University | Zhang Q.,Hunan University | And 2 more authors.
Solid State Communications | Year: 2013

Quasi-one-dimensional CdSe microstructures, including branched, needle-like and uniform microwires, have been successfully synthesized via a Sn-catalyzed thermal evaporation method. Possible growth mechanisms of these different CdSe microstructures are proposed. The optical properties of different CdSe microstructures were studied by the confocal optical microscope and obvious optical waveguide observed in the uniform microwire. The results indicate that efficient optical resonant cavities, dark excitons orientation not along the c axis and high crystallinity play a crucial role in optical waveguide performance of microstructure CdSe. © 2013 Elsevier Ltd. All rights reserved.


Alianelli L.,Diamond Light Source | Sawhney K.J.S.,Diamond Light Source | Malik A.,Micro Nano Technology Center | Fox O.J.L.,University of Bristol | And 4 more authors.
Journal of Applied Physics | Year: 2010

Diamond has unique properties which make it the ideal material for use in synchrotron instrumentation. X-ray optics made of diamond are almost transparent, they possess strength, and are subject to very low thermal expansion; therefore they will be able to withstand the powerful beams generated by fourth-generation light sources without compromising brilliance. For this reason, several groups are attempting fabrication of refractive lenses and zone plates made of diamond. Lithography and, in general, microfabrication technology, are the ultimate tools for the innovation of synchrotron focusing optics. We propose to combine modern silicon microtechnology with advanced deposition methods to fabricate nanocrystalline-diamond lenses for third- and fourth-generation synchrotron sources. The fabrication method is described here and microfocusing synchrotron tests are illustrated. © 2010 American Institute of Physics.

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