Structure and activity of iron-doped TiO2-anatase nanomaterials for gas-phase toluene photo-oxidation
Structure and activity of iron-doped TiO2-anatase nanomaterials for gas-phase toluene photo-oxidation
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DOI：
10.1039/c2cy20405c
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发表时间：
2013-02
影响因子：
5
通讯作者：
K. Christoforidis;A. Iglesias-Juez;S. Figueroa;M. Michiel;M. Newton;M. Fernández-García
中科院分区：
文献类型：
--
作者：
K. Christoforidis;A. Iglesias-Juez;S. Figueroa;M. Michiel;M. Newton;M. Fernández-García
利用同步辐射X射线全散射/衍射和吸收技术以及拉曼光谱研究了Fe掺杂纳米晶材料的结构（从局域到长程有序）和电子演化。这些方法与紫外可见光谱和红外漫反射（DRIFTS）相结合，以最大限度地提高这些材料的结构和形态信息的水平。Fe掺杂的纳米材料产生固体具有Fe在结构的取代位置，和阴离子空位作为电中性实体。这些结构修饰导致材料具有作为Fe含量的函数的降低的带隙能量。同时，观察到中间间隙电子状态出现。同时，Fe的存在改变了纳米晶的初级颗粒形状，而没有显著改变初级颗粒尺寸。与之前的结果相比，对综合结果的分析强烈表明，紫外光和可见光光催化活性在这里由形态问题而不是结构/电子问题主导。
The structural (from local to long range order) and electronic evolution of Fe-doped anatase nanomaterials is evaluated using in situ synchrotron based X-ray total scattering/diffraction and absorption techniques and Raman spectroscopy. These methods are combined with UV-visible spectroscopy and infrared diffuse reflectance (DRIFTS) to maximize the level of structural and morphological information regarding these materials. Fe doping of anatase nanomaterials generates solids having Fe at substitutional positions of the structure, and anion vacancies as charge neutrality entities. These structural modifications lead to materials with decreasing band gap energy as a function of Fe content. Concomitantly, mid-gap electronic states are observed to appear. At the same time, the presence of Fe alters the primary particle shape of the anatase without changing significantly the primary particle size. In contrast with previous results, analysis of the combined results strongly indicates that UV and visible photocatalytic activity are here dominated by morphological rather than structural/electronic issues.