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By using a double-aberration-corrected (scanning) transmission electron microscope (STEM/TEM) at an acceleration voltage of only 80 kV, we demonstrate that, due to the low solubility of copper (Cu) in carbon and its affinity with oxygen (O), single-crystal Cu catalysts dissociate into small cuprous oxide (Cu2O) nanoparticles after the growth of carbon nanofibers, and Cu2O nanoparticles ultimately localize on the fiber surfaces. This new finding is a step toward a better understanding of the interactions between Cu catalysts and carbon nanomaterials and could suggest a simple and effective method for eliminating Cu impurities from the fibers. [ABSTRACT FROM AUTHOR]

Abstract  Carbon-encapsulated copper nanoparticles were synthesized by a modified arc plasma method using methane as carbon source. The particles were characterized in detail by transmission electron microscope, high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray diffraction, thermogravimetric and differential scanning calorimetry. The encapsulated copper nanoparticles were about 30 nm in diameter with 3–5 nm graphitic carbon shells. The outside graphitic carbon layers effectively prevented unwanted oxidation of the copper inside. The effect of the ratio of He/CH4 on the morphologies and the formation of the carbon shell were investigated. [ABSTRACT FROM AUTHOR]

Helical carbon fibers were synthesized by the catalytic decomposition of acetylene as carbon source at low temperature of 240–260 °C with two nanocopper catalysts prepared by the hydrogen-arc plasma method and thermal decomposition of copper tartrate. Two growth modes for helical carbon fibers were obtained. One is mirror-symmetric growth mode, and the other is asymmetric growth mode. In the two growth modes, there were always only two helical fibers in regular shapes that were grown over a single copper nanoparticle. The two helical fibers had identical coil diameter, coil length, fiber diameter, cycle number, tight coil pitch, and cross section. In mirror-symmetric growth mode, the two helical fibers had absolutely opposite helical senses. The catalyst particle size was less than 50 nm and the coil diameter was <100 nm. Whereas in asymmetric growth mode, the two helical fibers had absolutely identical helical senses. The catalyst particle size was larger than 200 nm and their coil diameters reached 1 μm. The catalyst particle size had considerable effect on the growth mode for helical carbon fibers. [ABSTRACT FROM AUTHOR]

Abstract??The oriented ZnO nanorod arrays have been synthesized on a silicon wafer that coated with TiO2films by aqueous chemical method. The morphologies, phase structure and the photoluminescence (PL) properties of the as-obtained product were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffractometer (XRD), transmission electron microscope (TEM) and PL spectrum. The nanorods were about 100?nm in diameter and more than 1 ?m in length, which possessed wurtzite structure with acaxis growth direction. The room-temperature PL measurement of the nanorod arrays showed strong ultraviolet emission. The effect of the crystal structure and the thickness of TiO2films on the morphologies of ZnO nanostructures were investigated. It was found that the rutile TiO2films were appropriate to the oriented growth of ZnO nanorod arrays in comparison with anatase TiO2films. Moreover, flakelike ZnO nanostructures were obtained with increasing the thickness of anatase TiO2films. [ABSTRACT FROM AUTHOR]

Large-scale of oriented Polyaniline nanorods have been synthesized by one-step electrochemical deposition on aluminium electrode without the aid of any templates. The diameters and lengths of polyaniline nanorods are in the range of 50–60 nm and 150–250 nm, respectively. The morphologies and molecular structures of the film are characterized by field-emission scanning electron microscopy (FE-SEM), Ultraviolet-Visual (UV-vis) and Fourier transform infared (FTIR). The effects of synthetic parameters, such as the concentration of aniline and electric current intensity, on the morphologies of polyaniline films are investigated. [ABSTRACT FROM AUTHOR]

Nanostructured Fe3Al intermetallic compounds were produced by using hydrogen arc plasma method. The transmission electron microscopy experiments showed that the average particle size of the as-synthesized was about 40-nm. The change in hardness of Fe3Al nanostructured intermetallic compounds with annealing temperatures was observed and evaluated. [ABSTRACT FROM AUTHOR]

Mesoporous SiO2/Ni3Si2O5(OH)4 core–shell microspheres with tunable chamber structures have been synthesized by the reaction between Ni(Ac)2·4H2O and SiO2 microspheres via a simple self-template approach. [ABSTRACT FROM AUTHOR]

Analyzes the structure of polyhydro particles using HRTEM and the energy spectrum method. Preparation of nanocrystalline transition; Storage of hydrogen in nano transition metal particles; Ability of this stored hydrogen; Details on the structure of the shell and the core of hydrogen storage particles.