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Flower-like ZnO nanostructures, which consisted of sword-like ZnO nanorods, have been prepared by an organic-free hydrothermal process. The XRD pattern indicated that the flower-like ZnO nanostructures were hexagonal. The SAED and HRTEM experiments implied that the sword-like ZnO nanorods were single crystal in nature and preferentially grew up along the [001] direction. The effects of temperature, pH value and mineralizer on the morphology have been also investigated. It is considered that pH value is the main factor to influence the morphology because of its effect on the initial nuclei and growth environment of ZnO. Finally, the mechanism for organic-free hydrothermal synthesis of the flower-like ZnO nanostructure is discussed.

In this communication, we demonstrate a new approach to well-controlled growth of Se nanowires and nanotubes, which comprises a hydrothermal process and a following sonication. The hydrothermal process was used to derive Se particles of trigonal phase. In the subsequent sonication, if the Se particles were large enough, they were first broken, and then aggregated along the circumferential edge of the gap thus forming Se nanotubes; conversely, the Se particles were not broken and then aligned into nanowires. The high-resolution transmission electron microscopy (HRTEM) proved that both the Se nanotubes and nanowires were single crystalline in nature and 〈100〉 oriented. Based on a series of the TEM observation, a phenomenological mechanism for the elucidation of the controllable growth of Se nanowires and nanotubes is presented.

Long Bi2S3 nanowires have been prepared via the thioglyolic acid (HSCH2COOH, TGA) assisted hydrothermal method. The x-ray diffraction pattern shows that the Bi2S3 nanowires obtained are of orthorhombic phase. High resolution transmission electron microscopy identifies that the Bi2S3 nanowires are single crystalline in nature. Furthermore, we give a preliminary presentation of the mechanism for the TGA-assisted hydrothermal synthesis of Bi2S3 nanowires.

TiSi 2 is a high-melting compound with excellent conductivity ∼severalμΩcm. TiSi2 nanowires were fabricated in large scale by a simple vapor phase deposition method. The as-synthesized TiSi2 nanowires were investigated using x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman scattering. Field emission property of TiSi2 nanowires was studied and an emission current density of 5mA∕cm2 was obtained and no obvious degradation was observed in a life stability experiment period for over ∼40h. The cathodoluminescence images were very bright and homogenous. The remarkable performance reveals that the TiSi2 nanowires can serve as a good candidate for commercial application in vacuum microelectronic devices, particularly flat panel displays.