Surface Ti3+-Containing (blue) Titania: A Unique Photocatalyst with High Activity and Selectivity in Visible Light-Stimulated Selective Oxidation
Surface Ti3+-Containing (blue) Titania: A Unique Photocatalyst with High Activity and Selectivity in Visible Light-Stimulated Selective Oxidation
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DOI：
10.1021/cs300593d
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发表时间：
2012-12-01
期刊：
影响因子：
12.9
通讯作者：
Mul, Guido
中科院分区：
文献类型：
--
作者：
Hamdy, Mohamed S.;Amrollahi, Rezvaneh;Mul, Guido
采用高温一步法合成了含Ti3+-t的蓝二氧化钛。通过x射线粉末衍射（XRD）、紫外可见光谱（UV-vis）、拉曼光谱（Raman）和x射线光电子能谱（XPS）以及N-2吸附和解吸测试对制备的材料进行了表征。蓝色二氧化钛样品呈结晶状，表面积为22 m(2)/g。其相组成为85%的金红石和15%的锐钛矿，表面有大量的VO-Ti3+缺陷位点。与金红石相比，蓝钛表现出吸收红移，计算带隙为2.93 eV。在375 +/- 10 nm（紫外光）和425 +/- 10 nm（可见光）的光照条件下，考察了蓝二氧化钛液相选择性光氧化甲基环己烷（MCH）的光催化性能。利用衰减全反射-傅里叶变换红外分析监测活性。蓝色TiO2在两种波长下均表现出较高的活性。蓝二氧化钛的活性超过了其他（商用）二氧化钛催化剂（金红石和P25）的活性，特别是在425 nm处，并且对酮类的选择性也更高。活性数据与所研究的三种催化剂的性质有关，即结构，相组成和表面缺陷的存在与否，其中后者似乎在解释蓝二氧化钛的性能方面占主导地位。
A one-step synthesis procedure at elevated temperature was used to prepare Ti3+-tcontaining blue titania. The prepared material was characterized by X-ray powder diffraction (XRD), UV-vis, Raman, and X-ray photoelectron spectroscopy (XPS), and N-2 adsorption and desorption measurements. The blue titania sample was found to be crystalline, with a surface area of 22 m(2)/g. Its phase composition consists of 85% rutile and 15% anatase with a multitude of defect surface VO-Ti3+ sites. The blue titania showed an absorption red-shifted as compared to that of rutile, with a calculated bandgap of 2.93 eV. The photocatalytic performance of the blue titania was evaluated in the liquid phase selective photo-oxidation of methylcyclohexane (MCH) by illumination at 375 +/- 10 nm (UV) and 425 +/- 10 nm (visible light). The activity was monitored by attenuated total reflectance-Fourier transform infrared analysis. A high activity was observed for blue TiO2, remarkably equal in magnitude at both investigated wavelengths. The activity of the blue titania surpassed the activity of other (commercial) titania catalysts (rutile and P25), in particular at 425 nm, and the obtained selectivity for ketones was also greater. The activity data are discussed in relation to the properties of the three catalysts investigated, i.e., the texture, phase composition, and presence or absence of surface defects, of which the latter appears to be dominant in explaining the performance of the blue titania.