We report on the synthesis, structure, and self-assembly of single-wall subnanometer-diameter molybdenum disulfide tubes. The nanotubes are up to hundreds of micrometers long and display diverse self-assembly properties on different length scales, ranging from twisted bundles to regularly shaped “furry” forms. The bundles, which contain interstitial iodine, can be readily disassembled into individual molybdenum disulfide nanotubes. The synthesis was performed using a novel type of catalyzed transport reaction including C ₆₀ as a growth promoter.

Porous, well crystalline <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:mo>C</mml:mo></mml:math>LiFePO4/C composites with different amounts of carbon have been prepared by a sol-gel technique. The thickness of carbon coatings (paintings) has been determined by high-resolution transmission electron microscopy. It is shown that carbon coating thickness can be controlled by the amount of carbon and it has an impact on the obtained reversible capacity. Furthermore, it is shown that atomic ratio of nonactive Fe(III) phase (presumably <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">Fe</mml:mi><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub><mml:mo>P</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:math>Fe3P) in as-synthesized <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:mo>C</mml:mo></mml:math>LiFePO4/C composites depends on the amount of carbon in the composite. Using Mössbauer spectroscopy, we have confirmed that the nonactive Fe(III) remains nearly unchanged in the composite during cycling. The lowest amount of carbon in <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:mo>C</mml:mo></mml:math>LiFePO4/C composites obtained from citrate anion as a gelling agent was 3.2 wt % and this particular amount corresponds to the carbon coating thickness of about 1-2 nm. The reversible capacity obtained from the above-mentioned composite delivers close to 80% of the theoretical capacity at room temperature with a current density of 170 mA/g (C/1 rate). © 2005 The Electrochemical Society. All rights reserved.

We report the realization of field-effect transistors (FETs) made with chemically synthesized multilayer crystal semiconductor WS2. The Schottky-barrier FETs demonstrate ambipolar behavior and a high (∼105×) on/off current ratio at room temperature with current saturation. The behavior is attributed to the presence of an energy bandgap in the ultrathin layered semiconductor crystal material. The FETs also show clear photo response to visible light. The promising electronic and optical characteristics of the devices combined with the chemical synthesis, and flexibility of layered semiconductor crystals such as WS2 make them attractive for future electronic and optical devices.