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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]

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: Zinc blende (ZB) CdSe hollow nanospheres were solvothermally synthesized from the reaction of Cd(NO3)2·4H2O with a homogeneously secondary Se source, which was first prepared by dissolving Se powder in the mixture of ethanol and oleic acid at 205°C. As Se power directly reacted with Cd(NO3)2·4H2O in the above mixed solvents, wurtzite (W) CdSe solid nanoparticles were produced. Time-dependent experiments suggested that the formation of CdSe hollow nanospheres was attributed to an inside-out Ostwald ripening process. The influences of reaction time, temperature and ethanol/oleic acid volume ratio on the morphology, phase and size of the hollow nanospheres were also studied. Infrared (IR) spectroscopy investigations revealed that oleic acid with long alkene chains behaved as a reducing agent to reduce Se powder to Se2− in the synthesis. Photoluminescence (PL) measurements showed that the ZB CdSe hollow nanospheres presented an obvious blue-shifted emission by 42nm, and the W CdSe solid nanoparticles exhibited a band gap emission of bulk counterpart. [Copyright &y& Elsevier]

Abstract: Fe3O4 hollow microsphere chains with lengths of 8–11 μm have been solvothermally synthesized in the mixed solution of glycerol and water with 1 M NaOH. The hollow microspheres have diameters in the range 0.7–1 μm, and the thickness of the shells is 150–300 nm. The shell of the hollow microspheres is constructed by octahedrons of 100–170 nm. However, when the concentration of NaOH is adjusted to 3 M, the octahedron chains with lengths of 30–50 μm can be obtained. The magnetic saturation values of hollow microsphere chains and octahedron chains are 88.1 and 102.4 emu/g at room temperature, respectively. [Copyright &y& Elsevier]

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 concentration of the Mn(NO3)2 solution has significant influence on the morphologies and the phases of the MnO2 products. A large number of - MnO2 nanowires were prepared via a simple pyrolysis under lower reaction concentration. The nanowires have lengths up to tens of micrometers and diameters in the range of 20–100 nm. The - MnO2 nanobundles and nanoflowers were prepared by increasing the concentration of Mn(NO3)2 solution. The superparamagnetism of - MnO2 nanowires and paramagnetism of - MnO2 nanoflowers indicate their potential applications in magnetic materials. [Copyright &y& Elsevier]

Abstract: Bismuth sulfide nanorods were synthesized on a large scale via a simple self-sacrificing template route, by the direct reaction between the pre-prepared precursor metallic bismuth NT arrays and thiourea (Tu) in air at 100 ∘C for 16 h. XRD, TEM, SEM and HRTEM characterizations show that the prepared Bi2S3 samples are all phase pure and the Bi2S3 nanorods have uniform diameters of approximately 30–50 nm and lengths up to several micrometers. [Copyright &y& Elsevier]

Abstract: Uniform bismuth selenide hollow nanospheres were synthesized on a large scale in a mixed solvent of ethylene glycol (EG) and oleic acid (OA). The diameter of the Bi2Se3 hollow nanospheres is about 600 nm and the thickness of the shell is about 40 nm. The shape evolution of Bi2Se3 nanostructures with different volume ratios of EG and OA was also observed: nanoflakes in EG solution, hollow nanospheres as of 2/3, and finally flower-like nanostructures in OA solution. [Copyright &y& Elsevier]

Abstract: A convenient hydrothermal process was applied to prepare the cube-like MnSe2 microcrystallines through the reaction of MnSO4·H2O with Se and NaH2PO2·H2O in aqueous solution at 160°C for 12h. Powder X-ray diffraction (XRD) analysis confirmed that the product was the cubic phase of MnSe2 with cell parameter a=6.440Å. The chemical composition of the MnSe2 was determined by XPS. The Raman spectrum of MnSe2 presented the peaks of the Se–Se stretching mode at 232.44 and 266.58cm−1. The images of scanning electron microscope (SEM) and transmission electron microscope (TEM) showed the cube-like morphology of the product with the edge length ranging from 20 to 30μm. The formation mechanism of the MnSe2 microcrystallines was discussed as well. [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: Single crystalline nanobelts or nanoribbons and spherical or flower like hierarchical structures of α-MoO3 were obtained through homogeneous precipitation and subsequent hydrothermal treatment. It has been found that temperature, concentration of cationic surfactant cetyltrimethylammonium bromide (CTAB), and the addition order of reactants are the three critical factors for the assembly of nanobelts in the current process. [Copyright &y& Elsevier]

Abstract: Uniform ZnO urchin-like architectures were synthesized by hydrothermal decomposing Zn(OH)4 2− precursor with the assistance of dodecylamine (DDA) at 180°C for 12h. FESEM images display that the ZnO 3D urchin-like architectures are constructed of well-aligned ZnO nanorods with diameters of 50–80nm and lengths up to 2μm. Room temperature photoluminescence spectra of ZnO 3D architectures show an intensive ultraviolet emission at ∼385nm and weak green emission, which indicated their high structural and optical quality. [Copyright &y& Elsevier]

Abstract: By using t-Se powders and NaOH as starting materials, t-Se aligned microrod bundles, microtubes and dendrites were successfully grown through a reversible chemical reacting process under hydrothermal conditions. It is found that the quantity of MnCl2·4H2O, which served as the antalkali agent to control the reversible reaction, plays important roles in the morphology control of the final t-Se products. The possible mechanism of the formation of different morphologies was briefly discussed. [Copyright &y& Elsevier]

Abstract: Single-crystal MnOOH microrods were prepared hydrothermally by reducing KMnO4 with NH4Cl at 150°C for 24h. After the subsequent heat treatment of the as-prepared MnOOH microrods at 350°C for 10h in air, single-crystal beta-MnO2 microrods were obtained, which retained the similar morphologies of MnOOH microrods. The products were characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The influences of different reductants, the molar ratio between reaction materials, and temperature on the morphology and phase of the final products under hydrothermal conditions are discussed. The reaction temperature and reductant NH4Cl were crucial factors for the formation and morphologies of MnOOH microrods. Based on the experimental results and MnOOH crystal structure, a possible formation mechanism has been proposed on the growth of MnOOH microrods. [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]

Monodisperse Cu2O nanocubes are synthesized by reducing freshly prepared Cu(OH)2 with N2H4·H2O in water at room temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations show that most of these nanocubes are uniform in size, with the average edge length of ∼500 nm. Selected area electron diffraction (SAED) investigation reveals that these nanocubes are single crystalline. Further, Cu2O nanoboxes are obtained by etching Cu2O nanocubes with acetic acid solution at room temperature. The nanoboxes retain the size and external morphology of the nanocubes. [Copyright &y& Elsevier]

Boron nitride hollow spheres were synthesized by the reaction of BBr3 and NaNH2 at room temperature; X-ray powder diffraction pattern could be indexed as hexagonal BN with the lattice constants of a=2.482 and c=6.701 A˚; high-resolution transmission electron microscopy image showed the hollow spheres consisted of BN nanoparticles, with diameter between 80 and 300 nm; a possible formation mechanism of BN hollow spheres was discussed. [Copyright &y& Elsevier]

Mn5Si3 nanocages and nanotubes were successfully synthesized by molten salt flux reaction at 650 °C. The samples were characterized with X-ray powder diffraction and transmission electron microscopy. The influence of the reactants molar ratio of MnCl2 to Mg2Si and reaction temperature on the phases and morphologies of the products were discussed. The possible mechanism of forming Mn5Si3 nanocages and nanotubes is discussed. [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]

Hollow CdS nanospheres packed with square subunits were fabricated via microwave irradiation and pentaerythriol. The products were characterized with XRD, TEM, HRTEM, EDX and UV–vis spectrum. The results indicate that pentaerythriol is necessary in the formation of square subunits with high degree of crystallinity. A possible growth mechanism was proposed. [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]

The preparation of one-dimensional assemblies of PbS nanoparticles is described. By treating the suspension of PbCl2 powders in aqueous thioacetamide solution at 120 °C for 18 h, PbS nanoparticles were synthesized in regular chain-like patterns. The particles were less than 100 nm in sizes, and were organized into micron-length assemblies. The starting agents have much influence on the morphology of the products. The possible growth mechanism is also discussed. [Copyright &y& Elsevier]

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]

Abstract: A simple biomolecule-assisted hydrothermal approach was developed to synthesize antimony sulfide nanowires. The strategy presented here is the application of l-cysteine, acting not as complexing agent but also as sulfur source. The experimental results indicate that the reaction temperature is of importance for obtaining pure antimony sulfide. [Copyright &y& Elsevier]

Abstract: Well-oriented Cu2O films comprising of octahedral-shaped crystals were grown directly on copper foil via an hydrothermal treatment. The well-oriented films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Field emission from the film showed good emission properties, and, the electron emission turn-on field (E to) and threshold field (E thr) are about 9.6 and 13.4V/μm respectively, which is similar to the values reported for CuO nanofiber, although the latter has a much larger size. The corresponding Fowler–Nordheim (F–N) plots showed a linear behavior. The sharp corners of the tips are considered as main electron emitters and account for its good performance. [Copyright &y& Elsevier]

Nanocrystalline titanium diboride (TiB2) has been prepared through a reduction–boronation route by using Ti powders and BBr3 as titanium and boron sources, and metallic sodium as reductant at 400 °C. X-ray powder diffraction (XRD) pattern can be indexed as hexagonal TiB2 with the lattice constants of a=3.028 and c=3.223 A˚. Transmission electron microscopy images show particle morphology with average size of 15 nm. Selected area electron diffraction patterns confirm the preparation of the hexagonal TiB2. [Copyright &y& Elsevier]

B4C ultrafine powders were successfully synthesized at 450 °C through a new co-reduction route. The synthesis was carried out in an autoclave by using BBr3 and CCl4 as the reactants and metallic Na as the co-reductant. The X-ray powder diffraction pattern and Raman spectra indicate the formation of B4C. An atomic ratio of B to C of 4.09:1.0 was determined from X-ray photoelectron spectra. Transmission electron microscopy images shows that typical B4C crystallites are composed of uniform ultrafine spherical and rod-like particles. [Copyright &y& Elsevier]

Cerium hydroxycarbonate (CeOHCO3) with shuttle-like morphology has been conveniently synthesized at 90 °C from aqueous solution in the presence of polyvinylpyrrolidone (PVP). The products were characterized by X-ray diffraction, transmission electron microscopy and photoluminescent (PL) techniques. The as-prepared CeOHCO3 was found to have a PL emission at about 347 nm. Experimental conditions as well as the role of PVP played in the reaction were also explored. [Copyright &y& Elsevier]