Controlling the phase composition and photocatalytic activity of N doped TiO2

• Main Authors: Mu-Yuan, Li, 李牧遠
• Other Authors: Cheng-Liang, Huang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/bf7mqm

碩士 === 國立嘉義大學 === 應用化學系研究所 === 97 === Titanium dioxide is an useful photocatalyst, however, it doesn’t work well in the environment because it needs the UV light with the wavelength shorter than 380 nm to induce a heterogeneous photochemical reaction. One of the common methods to decrease the band gap of TiO2 is to dope the crystal with other elements or ions. This research focused on the preparations of nitrogen doped TiO2 by the sol-gel method. The amounts of ammonia and the calcined temperature were tuned to obtain the photocatalyst with different N-doped ratios and the different crystalline structures. The products, N-doped TiO2, are yellow color powders with irregular size ranging from 20 nm to 50 nm. XPS spectra of the as-prepared photocatalyst show the existence of nitrogen inside. FT-IR spectra demonstrate that ammonia was desorbed from the solid surface above 400 ℃. UV spectra show that N doped TiO2 could absorb visible light. Phase transition temperature of the as-prepared photocatalyst increases when the nitrogen is doped. It shows an indirect evidence that TiO2 is doped by nitrogen in the preparations. The experiment of degradation of R6G with the photocatalyst under irradiation of visible light shows the fact that the photoactivity increases when the weight fraction of anatase increases.