| dc.description.abstract | Titanium dioxide has been widely studied over the past decades owing to its excellent properties of low cost, chemical stability, nontoxicity, catalysis and so on. Additionally, one-dimensional TiO2 nanowires can provide a large surface area for effectively collecting photons or electrons. Meanwhile, enabling charge transfer along single direction thus the facilitation of carrier collections. TiO2 nanowires are frequently used in catalysis, sensors, dye-sensitized solar cells, Li-ion batteries and so on. Among them, hydrothermal method and thermal evaporation with VLS mechanism are two typical synthetic methods for preparing TiO2 nanowires. However, hydrothermal method needs to be followed by complex post-treatment in order to improve the poor crystallinity. Using the VLS mechanism also remain the metal-catalysts on the top of TiO2 nanowires.
Therefore, this research investigated Ge to enhance directly synthesis of large scale, uniform, well-aligned and free-catalyst TiO2 nanowires on the Ti substrate at various temperatures and thickness of Ge layer by horizontal tube furnace. The material structure included the TiO2 nanowires, TiO2 layer, GeO2 layer and Ti foil. It shows that the growth mechanism of TiO2 nanowire substrates utilize the x-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM) and Raman spectroscopy, which pertain to the composition distribution, crystal structure, surface morphology and nanowire morphology to obtain the function of Ge in this research.
Finally, the results provided a new catalytic effect of Ge on the growth TiO2 process, which enhance directly synthesis of large scale, uniform, well-aligned and free-catalyst TiO2 nanowires on the Ti substrate. We figure out the function of Ge to play in the reaction. Additionally, the TiO2 nanowires display an outstanding field emission property, well photocatalytic activity and wettability. | en_US |