Showing papers by "Zhaoping Liu published in 2004"
TL;DR: By employing various surfactants in the synthesis system, Te nanorods with well-controlled diameters and lengths could be reproducibly produced by this method, and it was observed that the as-synthesized nanorod with uniform size could be self-assembled into large-area smecticlike arrays.
Abstract: This article describes a surfactant-assisted approach to the size-controlled synthesis of uniform nanorods of trigonal tellurium (t-Te). These nanorods were grown from a colloidal dispersion of amorphous Te (a-Te) and t-Te nanoparticles at room temperature, which was first formed through the reduction of (NH4)2TeS4 by Na2SO3 in aqueous solution at 80 degrees C. Nuclei formed in the reduction process had a strong tendency to grow along the [001] direction due to the inherently anisotropic structure of t-Te. The formation of Te nanorods could be ascribed to the confined growth through the surfactant adsorbing on the surfaces of the growing Te particles. By employing various surfactants in the synthesis system, Te nanorods with well-controlled diameters and lengths could be reproducibly produced by this method. Both the diameters and lengths of nanorods decreased with the increase of the alkyl length and the polarity of the surfactants. Te nanorods could also be obtained in mixed surfactants, where the different surfactants were used to selectively control the growth rates of different crystal planes. We also observed that the as-synthesized nanorods with uniform size could be self-assembled into large-area smecticlike arrays.
162 citations
TL;DR: A facile solvothermal method by using mixed solvents for the large-scale synthesis of Bi(2)S(3) nanoribbons with lengths of up to several millimeters, which involves a special solid-solution-solid transformation as well as an Ostwald ripening process.
Abstract: This article describes a facile solvothermal method by using mixed solvents for the large-scale synthesis of Bi 2 S 3 nanoribbons with lengths of up to several millimeters. These nanoribbons were formed by a solvothermal reaction between Bi 1 1 1 -glycerol complexes and various sulfur sources in a mixed solution of aqueous NaOH and glycerol. HRTEM (high-resolution transmission electron microscopy) and SAED (selective-area electron diffraction) studies show that the as-synthesized nanoribbons had predominately grown along the [001] direction. The Bi 2 S 3 nanoribbons prepared by the use of different sulfur sources have a common formation process: the initial formation of NaBiS 2 polycrystals, which serve as the precursors to Bi 2 S 3 , the decomposition of NaBiS 2 , and the formation of Bi 2 S 3 seeds in the solution through a homogeneous nucleation process; the growth of Bi 2 S 3 nanoribbons occurs at the expense of NaBiS 2 materials. The growth mechanism of millimeter-scale nanoribbons involves a special solid-solution-solid transformation as well as an Ostwald ripening process. Some crucial factors affect nanoribbon growth, such as, solvothermal temperature, volume ratio of glycerol to water, and the concentration of NaOH; these have also been discussed.
151 citations
TL;DR: Sb 2 S 3 microcrystallites with a wealth of novel morphologies (patterns) have been prepared by a solvothermal reaction between antimony trisulfide and thiourea (thiosemicarbazide, thiocarbohydrate) at low temperature (140°C/150°C).
60 citations
TL;DR: A facile chemical route is reported for the synthesis of monodisperse nanocrystals of various metal sulfides and their assemblies into nanocrystal superlattices (NCSs); the sulfides NCSs were precipitated by adding ethanol to Nanocrystal colloids.
46 citations
TL;DR: In this article, a coordination self-assembly mechanism was proposed to elucidate the formation of the VO x · n H 2 O nanoribbons, which are up to ∼200μm in length, 100-150nm in width, 20-30nm in thickness, and grow along the [010] direction.
40 citations
TL;DR: Cubic fluoroperovskite KMnF3 nanostructures including acicular nanocrystals and ultrafine nanoparticles were solvothermally synthesized as discussed by the authors.
17 citations
TL;DR: In this article, a new isomer with $I^\pi = (10^ + )$¯¯¯¯ has been identified at an excitation energy E¯¯¯¯ x = 3.357 MeV, and the half-life was determined as $T_{1/2} = 94\pm10$386 ns.
Abstract: Excited states in 136Ba, populated in deep inelastic collisions by the interaction of 450 MeV 82Se ions with a 139La target, have been studied by means of in-beam $\gamma$
-ray spectroscopy. A new isomer with $I^\pi = (10^ + )$
has been identified at an excitation energy E
x
= 3.357 MeV. The half-life was determined as $T_{1/2} = 94\pm10$
ns. The extracted B(E2) value is much smaller than those in 132Te and 134Xe. This hindrance is investigated by a shell model calculation.
10 citations
TL;DR: In this article, single crystalline one-dimensional (1D) nanostructures of trigonal tellurium (t-Te) with well-controlled shapes and sizes were synthesized by the hydrothermal reduction of Na2TeO3 in a mixed solution of ethanol and water at 100°C.
Abstract: Single crystalline one-dimensional (1D) nanostructures of trigonal tellurium (t-Te) with well-controlled shapes and sizes were synthesized by the hydrothermal reduction of Na2TeO3 in a mixed solution of ethanol and water at 100 °C. The formation of various 1D nanostructures of t-Te was mainly determined by properly controlling the nucleation and growth rate of t-Te in different reaction media. In acidic solution (1 M of HCl), the reaction gave nanowires with diameters of ∼30–100 nm, while in alkaline solution (1 M of NaOH), it yielded tubular crystals with diameters of ∼1–2 μm. The diameters of tubular crystals could also be controlled by adjusting the NaOH concentration. When polymer surfactant poly(vinyl pyrrolidone)
(PVP) was presented in the alkaline solution, the reaction would produce uniform nanowires with diameters of ∼25 nm. Based on the TEM and SEM studies, the formation mechanisms for these 1D nanostructures were rationally interpreted. The crystallinity of the nanowires and the tubular crystals were determined by HRTEM, ED, and XRD.
2 citations