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Abstract: Microspheres assembled from carbon nanotubes (MCNTs), with the diameters ranging from 5.5 to 7.5μm, were synthesized by means of pyrolysis of polypropylene and maleated polypropylene in an autoclave. The characterization of structure and morphology was carried out by X-ray diffractometer (XRD), field-emission scanning electron microscopy (FESEM), (high resolution) transmission electron microscope [(HR)TEM)], selected-area electron diffraction (SAED) and Raman spectrum. As a typical morphology, the possible growth process of MCNTs was also investigated and discussed. The results of nitrogen adsorption–desorption indicate that the Brunauer–Emett–Teller (BET) surface area (140.6m2/g) of the MCNTs obtained at 600°C is about twice as that (74.5m2/g) of carbon nanotubes obtained at 700°C. The results of catalytic experiment show that MCNTs based catalyst has higher catalytic activity than the carbon nanotubes based catalyst for the preparation of methanol and dimethoxy-ethane by oxidation of dimethyl ether. [Copyright &y& Elsevier]

Nanocrystalline titanium diboride (TiB2) has been prepared by the reaction of TiCl4 with NaBH4 in the temperature range of 500–700 °C in an autoclave. X-ray powder diffraction (XRD) patterns can be indexed as hexagonal TiB2 with the lattice constants of a=3.032 and c=3.229 A˚. Transmission electron microscopy (TEM) image shows particle morphology, with average size of 15 nm for the powder obtained at 600 °C. Selected area electron diffraction (SAED) pattern confirms the prepared hexagonal TiB2. The oxidation behavior of TiB2 is studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). [Copyright &y& Elsevier]

Nanocrystalline CrN was synthesized from ammonolysis of CrCl3. The structure and morphology of the products were investigated by XRD, TEM and SAED. The influence of temperature and time on size of particles was also studied by XRD, TEM, SAED. Elemental analysis was carried out to establish the Cr:N atomic ratio of 1.04:1. XPS results further revealed that pure phase were obtained with the Cr:N atomic ratio of 1.05:1. [Copyright &y& Elsevier]

Ultrathin SnS 2 nanosheets modified sulfur/carbon (S/C-SnS 2 ) composites were synthesized through a facile method by mixing sublimed sulfur, Ketjen Black and ultrathin SnS 2 nanosheets. The ultrathin SnS 2 nanosheets can provide remarkable binding strength, large surface area and fast charge transfer, therefore leading to favorable chemical interaction with polysulfides in Li-S batteries. Accompanied with the synergistic effects between physical confinement of porous carbon and chemical interactions of SnS 2 , S/C-SnS 2 composites with different mass ratio of ultrathin SnS 2 nanosheets and C show much improved electrochemical properties. Among them, S/C-SnS 2 composite with 10 wt% of ultrathin SnS 2 nanosheets and 75 wt% of sulfur maintains superior long term cycling capacities of 800 mAh g −1 at 0.5 C after 300 cycles and 540 mAh g −1 at 2 C after 700 cycles. [ABSTRACT FROM AUTHOR]

Abstract: Hollow carbon octahedra with an average size of 300nm and a shell thickness of 2.5nm were prepared by a reaction starting from ferrocene and Mg(CH3COO)2·4H2O at 700°C for 10h. They became compressed and turned into deflated balloon-like octahedra when the reaction time was increased to 16h. It was proposed that the gas pressure generated during the reaction process induced the transformation from broken carbon hollow octahedra into deflated balloon-like compressed octahedra. X-ray powder diffraction and Raman spectroscopy indicate that the as-obtained carbon products possess a graphitic structure and high-resolution transmission electron microscopy images indicate that they have low crystallinity. Their application as an electrode shows reversible capacity of 353mAhg−1 after 100 cycles in the charge/discharge experiments of secondary lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Honeycomb-like graphitic macroporous carbon (HGMC) was synthesized by means of pyrolysis of NH4HCO3 using Mg powder as reductant in an autoclave at 550°C. The characterization of structure and morphology was carried out by X-ray diffraction (XRD), Raman spectrum, field-emission scanning electron microscopy (FESEM), and (High-resolution) transmission electron microscope [(HR)TEM]. The results of nitrogen adsorption–desorption indicate that the products are macropore materials with the pore size of 1–3μm, and the Brunauer–Emett–Teller (BET) surface area was 14m2/g. As a typical morphology, the possible growth process of HGMC was also investigated and discussed. The experimental results show that the in situ formed MgO microparticles play a template role during the HGMC formation. [Copyright &y& Elsevier]

Abstract: Three types of Eu3+-doped LaPO4 three-dimensional (3D) microstructures have been hydrothermally prepared by adjusting pH value and the molar ratio of La3+ and Eu3+ to phosphorus of Na5P3O10 (Ln/P) at 180°C. As the pH value was 0.15 and the molar ratio of Ln/P was in the range of 1/1 to 1/4, 5μm urchinlike spheres composed of long nanorods of hexagonal LaPO4:Eu were obtained. As the pH value was 1.00 and the molar ratio of Ln/P was 1/1, 3μm hollow spheres consisting of short nanorods of monoclinic LaPO4:Eu were prepared. Keeping the pH value at 1.0 and the molar ratio of Ln/P at 1/4, 6μm core–shell spheres of monoclinic LaPO4:Eu formed. Luminescent measurements were performed. Hollow spheres of monoclinic LaPO4:Eu had the strongest emission intensity. However, the emission intensity of monoclinic core/shell structure was even lower than that of hexagonal LaPO4:Eu urchinlike spheres. [ABSTRACT FROM AUTHOR]

Abstract: Porous soft magnetic material is a member of soft magnetic material family having large surface area. This kind of material has vast potential in the surface-related applications. In this paper, a kind of maghemite (γ-Fe2O3) with large surface area, 82.7m2/g, specifically, was obtained by the solvothermal method and subsequent calcining process. As shown in the test results, the maghemite microsphere has no magnetic memory in the magnetic field since the residual magnetization is 0.7emu/g. In the waste water treatment process, Rhodamine B, a model organic pollutant in the water, was removed through the adsorption and desorption cycles by the maghemite microspheres. The maghemite microspheres in the water can be recycled easily by a magnetic separation procedure and regenerated in ethanol at room temperature. [Copyright &y& Elsevier]

Abstract: The multi-armed CdS architectures can be synthesized from the reaction of the anhydrous CdCl2 and sulfur powders in ethylenediamine, in which a simple one-step reactant–solvent synchronous (RSS) co-assisted effect was proposed to be responsible to the growth of the multi-armed structures. The as-prepared products were characterized by XRD, XPS and TEM. In addition, their optical properties were also shown by UV–vis and fluorescence spectrum. FT-IR spectrum indicated that the dissociation of ethylenediamine molecule absorbed on the surface of CdS resulted in the formation of intermediate CdS(en) m−n cores and thus provided the condition for the anisotropy growth of CdS. The present technique may give a clue to grow the one-dimensional nano-sized semiconductors by the proper choice of the reactant and the solvent. [Copyright &y& Elsevier]

Abstract: Sb2O3 nanorods were successfully prepared via a mild hydrothermal route based on the reactions between SbCl3 and NH3·H2O in aqueous solution at 120–180°C for 12h. The as-prepared Sb2O3 nanorods were characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM), and X-ray photoelctron spectroscopy (XPS). Results showed that NH3·H2O played a significant role in the formation of Sb2O3 nanorods. The presence of NH3·H2O could greatly favor the reaction progress toward the right-hand side and led to the orientation growth of Sb2O3 nanorods. A possible mechanism for the formation of Sb2O3 nanocrystallites was discussed. [Copyright &y& Elsevier]

Submicron Se and Te rod-like crystals were successfully synthesized via a rapid polyol process by refluxing Na2EO3 (ESe, Te) and (NH3)2S2O3 in ethylene glycol at 180°C for 0.5h under vigorous stirring. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and XPS procedures. Studies found that reaction time and temperature have great influences on the morphology of the final products. [Copyright &y& Elsevier]

A new MnOOH precursor route has been developed to synthesize single-crystalline nanorods of tetragonal β-MnO2. Uniform γ-MnOOH nanorods were first prepared by reducing KMnO4 with KI under hydrothermal conditions at 120 °C. After calcination of the γ-MnOOH nanorods at 250 °C for 2 h in air, β-MnO2 nanorods retaining the morphologies of γ-MnOOH nanorods were obtained. The temperature, time and heating speed of calcination were found to be important for the morphologies of the β-MnO2 nanorods. [Copyright &y& Elsevier]

Nanocrystalline TiN, VN and CrN have been synthesized by a thermal nitridation reaction between the corresponding metal powder and NH4Cl at 600 °C in an autoclave. X-ray powders diffraction (XRD) indicated that these nanocystallites had a NaCl-type structure with lattice parameters: a=4.236 Å for TiN, 4.133 Å for VN, 4.145 Å for CrN. Transmission electron microscopy (TEM) showed these products consisted of cubic nanocrystals. X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) techniques revealed that all the products were almost pure nitrides. [Copyright &y& Elsevier]

Ag dendritic nanostructures were synthesized via a mild hydrothermal reaction using nickel nanotubes as reducing agent. The crystal morphologies changing from dendrite to compact crystals were investigated during the evolution of reaction system from non-equilibrium to quasi-equilibrium conditions. It was found that the strong shape anisotropy of Ni nanotube might influence the formation of dendritic patterns. The transition from silver dendrites to Ag compact crystals was investigated and the effect of surfactants is also discussed. [Copyright &y& Elsevier]

In this paper, we report the low-temperature synthesis of metal tungstate, MWO4 (M=Ca, Sr, Ba, Cd, Zn, Pb) nanocrystallites. By reaction between metal chloride and sodium tungstate in ethylene glycol at 180 °C for 10 h, well-crystallized tungstate particles were successfully obtained. Characterization by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) shows that the product powders consist of nanosize particles. Photoluminescence measurement reveals that the as-obtained CaWO4, CdWO4, and PbWO4 show excitonic peaks at about 430, 500 and 500 nm, respectively. The solvent and reaction conditions are important in the formation of the products. [Copyright &y& Elsevier]

Molybdenum carbide (Mo2C) has been synthesized via a sodium co-reduction of molybdenum pentachloride (MoCl5) and carbon tetrabromide (CBr4) in benzene at 350 °C for 12 h. X-ray diffraction (XRD) pattern indicated that the product was mainly hexagonal Mo2C with a small amount of cubic Mo2C. The lattice constants of the hexagonal Mo2C were a=3.009 and c=4.736 A˚. Transmission electron microscopy (TEM) study showed that the product consisted of slightly conglomerated particles of about 30 nm in size. [Copyright &y& Elsevier]

The novel polygonal flake like Ag8SnS6 crystal, Cu2FeSnS4 flaky, and well-dispersed Cu2CoSnS4 nanoparticles were successfully prepared via a convenient hydrothermal reaction route at relatively low temperature, which was avoiding the use of high temperature treatments or toxic organic solvents. The products were characterized by means of X-ray powder diffraction (XRD), transmission electronic microscopy (TEM), X-ray photoelectronic spectra (XPS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). It was found that the reaction temperature played a key role for the formation of the target products. [Copyright &y& Elsevier]

A simple and convenient polyol-mediated route has been developed to produce nanocrystalline Ag3SbS3 and Cu3SbS3 from AgNO3 and Cu(NO3)2 and SbCl3 with thiourea at 197 °C. The products were characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Analysis shows that glycol agitated state and injection rate have a great effect on the purity of the final products. [Copyright &y& Elsevier]

Nanocrystalline lead chalcogenides PbE (E=S, Se, Te) were synthesized conveniently by the reaction of Pb(CH3COO)2·3H2O and elemental chalcogens in ethylenediamine (en) under ultrasonic irradiation. XRD and TEM techniques were employed to characterize the products. The solubility of chalcogen in en was found to be the key factor of the reaction. A three-step mechanism was proposed to account for the formation of the products. [Copyright &y& Elsevier]

Micron-sized rod-like crystals of Cu2−xSe were successfully grown for the first time by a hydrothermal reaction from CuCl2·2H2O and Se powder at 60°C for 2 h. X-ray powder diffraction patterns (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM) images, and transmission electron microscope (TEM) images show that the product is cubic Cu2−xSe rod-like crystal and well crystallized. Hydrazine hydrate was used as solvent in the process and played an important role in the formation of rod-like Cu2−xSe crystals. The optical properties of Cu2−xSe, such as absorption spectra, photoluminescence (PL) spectra, and Raman spectrum are also reported for the first time. [ABSTRACT FROM AUTHOR]

LiNbO3 nanocrystal was successfully prepared via a simple and convenient hydrothermal route using LiOH and Nb2O5 as the reactants. Transmission electron microscopy images shows that the as-prepared sample displays a flake-like shape of 40–100 nm. X-ray diffraction, IR spectrum and Raman spectra of the as-prepared sample indicates that the sample was well crystalline and of high purity. [Copyright &y& Elsevier]

Nanocrystalline titanium carbonitride, TiC0.7N0.3, has been synthesized directly by a simple reaction route of TiCl4 and C3N3C13 using sodium as the reductant at 600°C. The composition of the powders has been investigated by X-ray powder diffraction. Transmission electron microscopy image reveals that the average size of the obtained particles is about 30 nm. [Copyright &y& Elsevier]

Layered nanocrystallines SnS and β-SnS2 were fabricated through a mild solvothermal route in the temperature range of 180–190°C. Reaction of thiourea with different tin sources (SnCl2·2H2O, SnCl4·5H2O or SnCl4) in organic solvents (benzene or ethanol) has been systematically investigated. By merely adjusting the proportion of the reactants, phase-pure SnS and β-SnS2 could be obtained, respectively. The resulting compounds were examined by XRD and TEM techniques. [Copyright &y& Elsevier]

Well crystallized PbS rods with the aspect ratios ranging from 2 to 12 were successfully synthesized in ethylenediamine by the so-called SSC route. X-ray powder diffraction, transmission electron microscopy and X-ray photoelectron spectra were used to characterize the as-obtained products. Several factors, such as temperature, synthetic procedure and solvent, which affect the morphologies of PbS nanoparticles were discussed. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline gallium nitride was synthesized by a solid-state reaction of metallic magnesium powder, gallium sesquioxide and sodium amide in a stainless steel autoclave at a relatively low temperature (400–550°C). The structures and morphologies of the obtained products were derived from X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). XRD patterns indicated that the products were hexagonal GaN (JCPDS card no. 76-0703). The influence of reaction temperature on size of the products was studied by XRD and TEM. Furthermore, the thermal stability and oxidation resistance of the nanocrystalline GaN were also investigated. It had good thermal stability and oxidation resistance below 800°C in air. [Copyright &y& Elsevier]