Controlled growth and characterization of one-dimensional nano-structured materials
As the research in nanomaterials is progressing at a rapid pace, it has become increasingly clear that the functionalization of the nanomaterials largely depends on the level of control in the fabrication of the nanomaterials. The main theme of this thesis is to develop a number of new techniques to fabricate one-dimensional nanostructured materials, study the growth processes and understand the growth mechanisms of the nanomaterials. The control over the nanomaterials growth was imparted by judiciously designing the synthesis experiments. Firstly, the ultra-thin β–Bi2O3 nanowires with a diameter down to 7 nm and a length of several μm have been successfully prepared for the first time using an oxidative metal vapor transport deposition technique. We also extended this technique for the controlled growth of thin ZnO nano-tetrapods. Secondly, the Kirkendall approach was first used to prepare ultra-thin, single crystalline ZnO nanotubes with inner and outer diameters of about 3 and 13 nm respectively. Thirdly, gold hollow tetrapods were prepared using ZnO tetrapods as the template, HAuCl4 as the gold source and ascorbic acid as the reducing reagent. Fourthly, we have successfully synthesized aligned ZnO nanowires and Cu(OH)2 nanoribbons on the corresponding Zn and Cu substrates through the gas-solution-solid method. Finally, the application of ZnO tetrapods and ultra-thin tube as humidity sensor was explored.