Bifunctional N-Doped Mesoporous TiO2 Photocatalysts
Bifunctional N-Doped Mesoporous TiO2 Photocatalysts
复制标题
双功能N掺杂介孔TiO2光催化剂
DOI：
10.1021/jp805926b
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发表时间：
2008-11-20
影响因子：
3.7
通讯作者：
Huang, Weixin
中科院分区：
文献类型：
--
作者：
Fang, Jun;Wang, Fang;Huang, Weixin
用氢氧化铵低温沉淀草酸钛配合物[TiO(C2O4)(2)](2-)，然后在不同温度下焙烧制备了可见光活性的介孔掺氮TiO2光催化剂(N-TiO2光催化剂)。用粉末X射线衍射仪、N-2吸附-脱附等温线、红外光谱、漫反射紫外可见光谱、X射线光电子能谱和透射电子显微镜等手段对N-TiO2光催化剂的结构进行了详细的表征。利用程序升温反应光谱研究了催化剂前驱体的焙烧过程。N-TiO2光催化剂在光降解甲基橙中表现出相当的紫外光和可见光活性。掺杂的N物种位于二氧化钛的间隙位置，导致了二氧化钛的带隙变窄。一个新颖而有趣的结果是，在400℃焙烧的N掺杂二氧化钛(N-TiO2400)具有共价键合的二羧基产生的Bronsted酸位，这大大提高了对甲基橙的吸附能力。N-TiO2400催化剂是一种很有前途的吸附-光降解一体化催化剂，同时也是一种很有前途的酸催化-光催化双功能催化剂。
We have successfully prepared visible-light-active mesoporous N-doped TiO2 (N-TiO2) photocatalysts by the precipitation of titanyl oxalate complex ([TiO(C2O4)(2)](2-)) by ammonium hydroxide at a low temperature followed by calcination at different temperatures. The structures of N-TiO2 photocatalysts have been characterized in detail by means of powder X-ray diffraction, N-2 adsorption-desorption isotherms, infrared spectroscopy, diffuse reflectance UV-vis spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscope. The calcination process of the catalyst precursor was also studied by means of temperature-programmed reaction spectroscopy. N-TiO2 Photocatalysts exhibit comparable UV-light activity and visible-light activity in the photodegradation of methyl orange. The doped N species locates at the interstitial sites in TiO2, which leads to the band gap narrowing of TiO2. A novel and interesting result is that N-doped TiO2 calcined at 400 degrees C (N-TiO2-400) has Bronsted acid sites arising from covalently bonded dicarboxyl groups, which greatly enhances the adsorption capacity for methyl orange. The N-TiO2-400 catalyst is a promising adsorption-photodegradation integration catalyst; meanwhile, it is also a promising acid catalysis-photocatalysis bifunctional catalyst.