| Summary: | 碩士 === 國立臺北科技大學 === 環境規劃與管理研究所 === 94 === Photochemical reactions catalyzed by semiconductors have been investigated extensively in the degradation of toxic organic pollutants, in organic synthesis and in energy conversion and storage. Titania is a semi-conducting photocatalyst. It can decompose the organic pollutant by irradiation under UV light. This study is divided to prepare TiO2-xNx by calcined Degussa P-25 and NH4Cl. The final propose is decreased the bandgap of TiO2, and let it can be catalyzed in the visible light.
This study demonstrates a simple route for the preparation of nanocrystalline N-doped titania by calcined with ammonia chloride. This study have two important parameters: calcined temperature(T) and the ratio of TiO2 to NH4Cl(R). The N-doped titania we made was characterized by ESCA, XRD, BET and TEM etc.
The wavelength of absorption of N-doped we prepared by calcination with ammonia chloride was shifted to the range of visible light.The ESCA measurement showed that nitrogen was surely doped in the titanium oxide, and the highest nitrogen content in TiO2-xNx is 11.83%. the sample is RT-1:6-400. The XRD measurement showed that Anatase phase easily transformed to Rutile phase at 500℃ and above. The crystalline transformed rate become higher by the higher calcined temperature and higher ratio of TiO2 to NH4Cl.
The best photocatalytic activity in the degradation of methylene blue is obtained at the N loading about 11.83at%. The film exhibits the degradation of methylene blue with a rate-constant(k) about 0.0512 h-1 and decrease 150 hours to remove the methylene blue.
Final, the RT-1:6-400 have the best efficiency photacatalisis is. It is sure the the NH4Cl is a nice material to be the N source by HCl(g) produce in the high calcined temperature with TiO2 and NH4Cl.
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