二氧化钛系列光催化剂的拉曼光谱

Raman Spectroscopy of Titanium Dioxide Photocatalyst

采用溶胶 -凝胶法制备了 Ti O2 粉体和薄膜光催化剂 .使用 FT-Raman光谱和激光共聚焦拉曼光谱研究了粉体和薄膜的拉曼光谱 ,探讨了热处理条件、Fe3 +掺杂和以硅胶为载体的薄膜化所引起的 Ti O2 结构变化 .结果表明 ,Ti O2 在 35 0℃存在由无定形向锐钛矿相的转变 ,6 0 0℃下存在锐钛矿相向金红石相的转变 ,75 0℃下完全转变为金红石相 ;掺杂会引起 Ti O2 的晶格畸变 ,导致拉曼谱峰宽化 ;以硅胶为载体的 Ti O2 负载薄膜的部分拉曼谱峰与粉体相比 ,有一定的位移和宽化 .

Nano-size TiO 2, Fe 3+-TiO 2, TiO 2/SiO 2, and Fe 3+-TiO 2/SiO 2 were prepared by sol-gel method. The structural change of TiO 2 caused by different calcining conditions, Fe 3+-doped contents, and formation of film on silica were studied by FT-Raman and confocal Raman technologies. The experimental results show that the different crystalline phases were observed at different calcinating temperatures. The titanium dioxide powder heated at 350-550 ℃ for two hours forms an anatase phase. The anatase phase materials transforms to rutile phase at 600 ℃ and transits completely to rutile phase calcining for two hours at 750 ℃. After doping Fe 3+, the FWHM at 144 cm -1 of Fe 3+-TiO 2 and Fe 3+-TiO 2/SiO 2 is broadened apparently compared with that of TiO 2 and TiO 2/SiO 2, respectively. Some peaks of TiO 2/SiO 2 coating film has some shift and broadening compared with those of TiO 2.