高分子辅助水热制备单晶碲纳米管

Te single-crystal nanotubes were synthesized using Na₂TeO₃ and (NH₂)₂CS as starting materials and pol-yacrymide (PAM) as morphology-director under hydrothermal conditions. The obtained products were characteri-zed by XRD, FESEM, SEM and TEM techniques. The results show that Te nanotubes grow along c axial with the inner diameters of 100～500 nm, wall thickness of 80～160 nm and lengths of 5～10 μm. A possible mechanism for the growth of Te nanotubes was discussed.     

VOx / Titanate复合材料纳米棒的水热合成及其电化学性能研究

Vanadium oxide/titanate composites nanorods (VO_x/ Titanate-CNRs) were synthesized in high yield by using titanate nanotubes as templates and V₂O₅·nH₂O sol as the precursors under hydrothermal conditions (200 ℃, 48 h). Samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive analysis by X-ray (EDAX). X-ray diffraction structure determination showed that this new phase had the composition of V₃O₇·H₂O and crystallized with orthorhombic symmetry. SEM and TEM tests showed that the samples were uniform straight rods with the diameter range from around 100 to 300 nm and the length over 10 μm. The chemical compositions of the samples were determined with EDXA. The electrochemical tests of samples (titanates nanotubes, V₂O₅ and VO_x/ Titanate-CNRs) prove that VO_x/ Titanate-CNRs exhibit a better electrochemical performance.     

Fe/La2O3纳米催化剂制备碳纳米管

Nanocrystalline LaFeO₃ was synthesised by the citrate method with La(NO₃)₃·6H₂O,Fe(NO₃)₃·9H₂O and citric acid as the raw materials. Before and after reduction, its structure was characterized by means of X-ray diffraction and transmission electron microscopy(TEM). And after reduction of LaFeO₃ oxide, the rare earth oxide, La₂O₃, prevents Fe particles from agglomerating and promotes the dispersion of nano-scale Fe particles (ca.40nm), which is one of the key factors for the growth of carbon nanotube. The carbon nanotubes from the catalytic de-composition of C₂H₂ were obtained using Fe/La₂O₃ nano-scale catalyst, which was formed from LaFeO₃ oxide as the catalyst precursor. The morphological structures of the carbon nanotube obtained have been examined by TEM. The results indicate that they are multi-walled nanotubes of good quality with inter diameter ranging from 20～25nm and length ranging from 25～40μm. The yields of carbon nanotube are 1.25g·gcat^-1 at the reaction temperature of 973K for 30min.     

水热法合成K0.5Bi0.5TiO3纳米陶瓷粉体

K_0.5Bi_0.5TiO₃(KBT)nanocrystalline particles were hydrothermally synthesized from Bi(NO₃)₃·5H₂O, TiO₂ and KOH. The crystal phase, chemical composition and microstructure were characterized by XRD, XRF, Raman scattering spectroscopy and TEM. The results indicated that the products were pure perovskite structured K_0.5Bi_0.5TiO₃ with chemical stoichiometry and perovskite structure. The TEM observation revealed that the particles possessed a feature of cubic shape and a nano-scale of about 40 nm. The KBT ceramics sintered at 1 040 ℃ from hydrothermal powders show higher density and better electric properties than that prepared by a solid-state reaction method.     

一维Y2O3∶Eu3+纳米发光材料的制备与表征

One-dimensional Y₂O₃∶Eu³⁺ luminescence nanomaterials were prepared by hydrothermal method without template, and their properties were characterized. XRD patterns show that the precursors are hexagonal phase Y(OH)₃ crystals, and the samples are cubic Y₂O₃ after heat-treatment. SEM images indicate that the one-dimensional material with a diameter of 100 nm and length of micrometer scale can be obtained by this hydrothermal method. Photoluminescence properties show that the position and intensity of the precursors are different with that of the heat-treated samples resulted from the different hosts.     

溶胶-凝胶涂附电纺纳米纤维制备ZrO2纳米管

Stable zirconia sol was prepared using inorganic salt(zirconia chloride octahydrate) as the precursor and H₂O₂ as the catalyst. ZrO₂-PBS coaxial nanofibers were fabricated using the sol-gel coating technique to filling poly butylenes succinate(PBS) fibers with zirconium dioxide by electrospun. ZrO₂ nanotubes were obtained via calcining ZrO₂-PBS coaxial nanofibers. The ZrO₂ nanotubes were characterized by TG, SEM and TEM, respectively. The results show that ZrO₂ nanotubes with a diameter of 50～100 nm are obtained after calcining ZrO₂-PBS coaxial nanofibers at 450 ℃.     

水热改性对NiMo/γ-Al2O3加氢脱氮催化剂结构及性能的影响

The influence of hydrothermal modification on the structure and hydrodenitrogenation (HDN) activity of NiMo/γ-Al₂O₃catalyst was studied in the range 140～180 ℃. The experimental results indicated that the hydrodenitrogenation reaction rate of pyridine was accelerated using the NiMo/γ-Al₂O₃catalyst synthesized via hydrothermal route due to the change of the structure, the increase of the amount of Mo and Ni and the rise of the specific surface area. The change of the structure of catalysts was enhanced at higher hydrothermal temperature, producing NiMo/γ-Al₂O₃catalyst with better HDN activity.     

水热法合成纳米氧化铪及碳/氧化铪核壳结构纳米复合粉体的研究

Nano-sized HfO₂, C and C/HfO₂ powders obtained through hydrothermal process have been investigated by XRD, TEM and FTIR, and Different precursors, namely Hafnium(Ⅱ) oleate and Hafnium(Ⅱ) hydroxide derived from homogeneous precipitation method, have been chosen for the synthesis of nanometric HfO₂ via hydrothermal process. The results indicate that using the former material as the precursor under identically hydrothermal process can yield finer HfO₂ nanoparticles, compared to using the latter. Nano-sized Carbon of about 100 nm with square morphology and narrow size distribution can be obtained through hydrothermal reaction of sucrose solution at 200 ℃ for 6 h. The addition of as-synthesised Carbon nanoparticles into the hydrothermal process of HfO₂ powder can produce C/HfO₂ composite powders with core-shell structure.     

Cu-Ni/La2O3热解C2H2制备碳纳米管的研究

Nano-sized and well-dispersed Cu-Ni/La₂O₃ can be obtained by reduction of LaCu_0.2Ni_0.8O₃ with the structure of perovskite. Using Cu-Ni/La₂O₃ as catalyst and C₂H₂ as carbon source, carbon nanotubes with a high yield and narrow diameter distribution can be obtained in the reaction temperature range of 650～700℃. Outer diameter of carbon nanotubes rangs from 9nm to 14nm. TG, Raman and XPS analysis indicate that carbon nanotubes prepared by Cu-Ni/La₂O₃ are relatively higher in graphitic degree.     

水热法制备高纯超细CeO2-ZrO2复合氧化物

Superfine composite powders of CeO₂-ZrO₂ (CZ) and CeO₂-ZrO₂-La₂O₃ (CZL) were prepared by hydrothermal method. The effects of pH、temperature and time for hydrothermal process on the performance of the resulting powders were studied. The optimized reaction parameters were on follows: the precursor′s pH≈9.0, hydrothermal temperature of 200 ℃ holding for 2 h. Thermal stable powders with average particle size smaller than 10 nm and specific surface area of 171 m²·g^-1 were obtained. A BET specific surface area was still at 44 m²·g^-1 after calcination at 1 000 ℃ for 6 hours.     

TiO2纳米管负载Ag、Au、Pt纳米粒子的微波合成与表征(英)

TiO₂ nanotubes were prepared under normal pressure at a temperature of 120 ℃. Ag, Au, Pt nanoparticles supported on TiO₂ nanotubes were prepared by microwave assisted heating polyol process. TEM images showed that microwave prepared Ag, Au, Pt nanoparticles supported on TiO₂ nanotubes were small and well dispersed on the surface of the TiO₂ nanotubes. UV-Vis absorption spectra showed that the absorbance of Ag/TiO₂ nanotubes and Au/TiO₂ nanotubes in the visible light range increased greatly compared to the single titania nanotubes.     

α-MnO2和β-MnO2纳米棒的制备和催化性能研究

α-MnO₂ and β-MnO₂ nanorods were prepared directly by facile hydrothermal process at 150 ℃ and 220 ℃, respectively. The as-prepared α-MnO₂ and β-MnO₂ nanorods were shown to be phase-pure single crystallites as evidenced by XRD, TEM and SEM results. Further experiments show that the as-prepared α-MnO₂ and β-MnO₂ nanorods have catalytic effect on the oxidation and decomposition of the methylene blue(MB) dye with H₂O₂. The catalytic activity of β-MnO₂ is much higher than that of α-MnO₂.     

不同形态的α-Fe2O3纳米粉体的水热合成、表征及其磁性研究

Four different hematite (α-Fe₂O₃) nanopowders with various morphologies have been synthesized in the presence of surfactant (HPC) via hydrothermal route at 180 ℃, using four kinds of iron salts, Fe₂(SO₄)₃, FeC₂O₄, FeSO₄ and (NH₄)₃Fe(C₂O₄)₃, as precursor materials. The products were characterized by means of X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared spectroscopy (FTIR) and magnetization measurements. The hysteresis measurements show that the products exhibit weak ferromagnetic property at room temperature. It is concluded that the different precursor materials and the presence of the surfactant are important factors that exert significant effects on the morphologies and magnetic properties of the products.     

一维链状配位聚合物[Ag(bix)(NO3)(H2O)]n的合成和晶体结构

A one-dimensional (1D) Z conformation coordination polymer, [Ag(bix)(NO₃)(H₂O)]_n was obtained by the reaction between AgNO₃ and flexible ligand of 1,4-bis(imidazol-1-ylmethyl)-benzene under hydrothermal conditions. It crystallizes in triclinic with space group P1. The crystallographic data of the compound are: a=0.777 1(2) nm, b=1.043 4(3) nm, c=1.082 7(3) nm, α=71.403(4)°, β=80.946(5)°, γ=88.794(4)°. The 1D chainlike structure was connected by π-π interaction between phenyl rings, leading to a 2D layered network. The lattice water and the NO₃^- anions were involved between the layers, therefore the 2D layered structure further extended to an intricate 3D framework. CCDC: 257100.     

溶剂热还原合成Cr2O3纳米管(英)

Cr₂O₃ nanotubes with diameters of 80 nm and lengths of 550 nm were synthesized in a solvothermal reduction system at 180 ℃. The acetyl acetone (AcAc) and ethylene glycol (EG) were used as the chelate agent and the reductant respectively in the system. An intermediate compound-Cr(Ⅲ)(C₅H₇O₂)₃ was formed to force Cr₂O₃to crystallize along one direction.     

水热法制备具有光滑表面的球形Y2O3∶Eu3+发光材料

The spherical Y₂O₃∶Eu³⁺ luminescent particles with size of 0.5～3 μm and smooth surface were synthesized by hydrothermal method. The resulted Y₂O₃∶Eu³⁺ precursors and the calcined particles were characterized by differential thermal analysis (DTA) and thermogravimetric (TG) analysis, X-ray diffraction (XRD), Fourier-transform IR spectroscopy (FTIR), scanning electron microscopy (SEM) and photoluminescence spectra (PL). FTIR, TG-DTA, XRD measurements show that the precursors are crystal with hydroxyl and carbonate group, and the pure cubic yttria is obtained after annealing above 700 ℃. The SEM images indicate that the Y₂O₃∶Eu³⁺ particles are in spherical shape and with smooth surface. PL analysis shows that the particles present characteristic red emission of Eu³⁺.     

一种制备大量氧化锌纳米管的简单方法(英)

ZnO nanotubes were synthesized in large scale by thermal decomposition of the precursors obtained via chemical reaction between Zn(CH₃COO)₂·2H₂O and NaHCO₃ in the presence of surfactant sodium dodecyl sulfate (SDS). The inner diameters of the tubes were in the range of 80～100 nm, and outer diameters in the range of 160～260 nm with lengths up to a few micrometers. The products were characterized with XRD, TEM, and SEM.     

V2O3纳米粉末的固相反应合成(英)

Vanadium sesquioxide (V₂O₃) nanopowder was successfully prepared by the solid phase reaction of the mixture of vanadyl hydroxide (VO(OH)₂) and ammonium chloride (NH₄Cl) at 500 ℃. The as-obtained samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). V₂O₃ nanoparticles were well dispersed and displayed sphere-like particles with diameters in the range of 30～50 nm.     

BaTiO3/ IPNs的制备及介电性能与阻尼性能的相关性

BaTiO₃/ Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO₃nanocrystal in tetragonal system and polyurethane(PU) / unsaturated polyester (UP) interpenetrating polymer networks (IPNs). The tetragonal nanocrystalline BaTiO₃was obtained by hydrothermal process and calcination at 1 200 ℃. The prepared materials were polarized with high voltage and small current, and protected by silicon oil. The morphology of BaTiO₃/ IPNs and the effect of combination of BaTiO₃on the damping behavior of IPNs were studied. The relationship between damping performance and dielectric charater was also discussed in terms of dielectric constant and dielectric loss measured. The results show that the areas under loss modulus (E″) and the values of loss factors (tanδ) were both increased by combination of BaTiO₃into IPNs system. The maximum value of E″ increased above 100 MPa compared with pure IPNs and the extent increased more remarkably after polarizing process. The main and shoulder peak of tanδ curves both moved toward higher temperature ranges, and the temperature ranges of tanδ>0.3 was higher than 100 ℃. Moreover, through polarizing process, the composites exhibited synergistic action caused by elastomeric damping, interfacial abrasive damping and piezoelectric damping mechanisms. The relationship study of damping property and dielectric characters showed that the temperature ranges exhibited excellent consistency of maximum dielectric loss and modulus with damping loss factor.     

微波溶剂热法合成纳米晶Cu2SnSe4及其结构研究

The nanocrystal Cu₂SnSe₄ was synthesized by the microwave solvothermal technique and characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Results show that the technique is fast, simple and energy saving, and the average size of the product is 20～30 nm. Optical absorption spectrum of Cu₂SnSe₄ shows that product with a band gap of 2.36 eV is a better semiconductor.