Preparation, Characterization and Catalytic Applications of Titania Nanotubes

• Main Authors: Yi-Rong Lai, 賴怡蓉
• Other Authors: Shu-Hua Chien
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/79211552364186604394

碩士 === 國立中央大學 === 化學研究所 === 93 === Titania nanotubes were prepared by hydrothermal method and characterized by atomic absorption spectroscopy (AAS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption iso- therm and diffuse reflectance ultraviolet- visible spectroscopy (UV-vis). The N2 adsorption/desorption isotherm experiment indicated that Dnt exhibits high surface area (385 m2/g), which is much higher than that of the raw TiO2 Degussa P25 (50 m2/g). The diameter of nanotubes was about 8 to 10 nm with the inner diameter of ca. 6 to 8 nm from HRTEM observation. XRD and Raman spectroscopy indicated that the crystal phase of Dnt is very different from Degussa P25, which is neither the anatase nor the rutile. The effects of calcination condition of the TiO2-nanotubes were studied in this research. The surface area reduced progressively and the morphology changed from nanotube-shaped to particle form along with the increase of calcination temperature. The crystal phase of Dnt was changed to anatase after calcination between 300 and 400 oC. The photocatalytic activity of Dnt was evaluated by photobleaching of methylene blue. The activity of the Dnt is poorer than that of the Degussa P25, but being improved significantly by calcination. The results suggested that the photocatalytic activity is dominated by the crystal phase and not the surface phase. TiO2-nanotube supported Ag catalysts were prepared by incipient-wetness impregnation and direct hydrothermal method. Temperature-programmed desorption of NO (NO-TPD) indicated that the hydrothermal sample exhibits higher capability for NO adsorption and decomposition of NO to N2.