Study On Hydrothermal Synthesis And Growth Mechanism Of Chalcogenide Nanomaterials

Inorganic semiconductor nanomaterials have attracted widespread concern and further research due to their excellent physical and chemical properties. Transition metal chalcogenides are important part of that and have been widely application prospects, because of their unique optical, electrical, catalytic, and magnetic properties, especially that the ⅠB, ⅡB group metal chalcogenides have been more widely used in many areas. In order to expand the research and applications of transition metal chalcogenides nanomaterials, ZnS and CuS (the representative nanomaterials) were prepared in this article. The growth mechanism of each structure was researched and the detail results are follows:(1) Urchin-like ZnO architectures with the smooth and regular hexagonal prism nanorods were synthesized by hydrothermal process without any surfactants or templates. We also obtained the ZnO/ZnS heterogeneous architectures which the ZnS nanoparticles are studded over the surface of ZnO nanorods and the endpoint of each nanorods is needle like ends which is different from the pure ZnO nanorods. The Zn-O vibration in the ZnO/ZnS heterogeneous architectures shows a slight red shift toward1400cm-1compared with that of the pure ZnO products. The growth mechanisms of ZnO and ZnO/ZnS heterogeneous architectures were discussed, it can provides scientific basis and direction for the further research to the ZnO and ZnO/ZnS with different morphology.(2) The standard hexagonal copper sulfide nano hollow tube products were synthesized by hydrothermal process at160℃with copper chloride and thioacetamide as raw materials under sodium hydroxide solution. The size of product is uniform with a diameter of ca.100-170nm and length of1.5-3urn. The growth mechanism of copper sulfide nano hollow tube structures was researched and the effects of various kinds of experiment conditions on the morphology were also researched, for example: the amount of sodium hydroxide, the reaction temperature, the reaction time, the reactant concentration. The results indicate that the morphology of products is flocculent and disorderly and unsystematic without sodium hydroxide, the size and the diameter of copper sulfide nano-hollow tube increase while reduction of the reaction temperature or increasing of the reaction time, the unformed nanosheets were appeared with the change of the reactants concentration. In the infrared region, the absorption peaks at1110cm-1is the characteristic absorption peaks of Cu-S. UV-Vis spectra show that red shift was appeared with increasing of the reaction time or reduction of reaction temperature.(3) The standard hexagonal copper sulfide nanoplates were synthesized by hydrothermal process at150℃with copper chloride and sodium thiosulfate as raw materials in the supporting of hexadecyl trimethyl ammonium bromide. The product is a regular hexagon, the size is270nm. The growth mechanism of copper sulfide nanoplate structures which were obtained in the supporting of CTAB was researched and the effects of various kinds of experiment conditions on the morphology were also researched, for example:the amount of surfactant, the reaction temperature, the reactant concentration. In the infrared region, the absorption peaks at1085cm-1is the characteristic absorption peaks of Cu-S and the spectra shows the red shift of25cm-1compared with that of copper sulfide nano hollow tube structures. UV-Vis spectra show that the different morphologies of nanostructures will express significantly different absorption spectra.