A New Photoactive Crystalline Highly Porous Titanium(IV) Dicarboxylate
A New Photoactive Crystalline Highly Porous Titanium(IV) Dicarboxylate
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DOI：
10.1021/ja903726m
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发表时间：
2009-08-12
影响因子：
15
通讯作者：
Ferey, Gerard
中科院分区：
文献类型：
--
作者：
Dan-Hardi, Meenakshi;Serre, Christian;Ferey, Gerard
钛由于其低毒性、氧化还原活性和光催化性能而成为一种非常有吸引力的MOFs候选物。我们在这里介绍MIL-125，高度多孔和结晶二羧酸钛（IV）（MIL代表拉瓦锡研究所的材料）的第一个例子，具有高热稳定性和光化学。特性.它的结构是建立从八聚体轮的伪立方排列，建立了从边或角共享钛八面体，和对苯二甲酸二价阴离子导致一个三维的周期性阵列的两种类型的混合笼与可访问的孔径为6.13和12.55埃。X-射线热衍射法和热分析表明，MIL-125在空气气氛下高达360 ℃是稳定的，而氮吸附分析表明表面积（BET）为1550 m2·g（-1）。此外，在氮和醇吸附下，MIL-125表现出与形成稳定的混合价钛氧化合物相关的光致变色行为。钛氧簇在氧的存在下被反氧化。通过电子自旋共振（ESR）和紫外-可见吸收光谱的结合使用，这种光化学现象进行了分析。光生电子被捕获的Ti（III）中心，而伴随的氧化吸附的醇分子发生。这种新的微孔杂化材料在智能光子器件、传感器和催化等方面具有很好的应用前景
Titanium is a very attractive candidate for MOFs due to its low toxicity, redox activity, and photocatalytic properties. We present here MIL-125, the first example of a highly porous and crystalline titanium(IV) dicarboxylate (MIL stands for Materials of Institut Lavoisier) with a high thermal stability and photochemical. properties. Its structure is built up from a pseudo cubic arrangement of octameric wheels, built up from edge- or corner-sharing titanium octahedra, and terephthalate dianions leading to a three-dimensional periodic array of two types of hybrid cages with accessible pore diameters of 6.13 and 12.55 angstrom. X-ray thermodiffractometry and thermal analysis show that MIL-125 is stable up to 360 degrees C under air atmosphere while nitrogen sorption analysis indicates a surface area (BET) of 1550 m(2).g(-1). Moreover, under nitrogen and alcohol adsorption, MIL-125 exhibits a photochromic behavior associated with the formation of stable mixed valence titanium-oxo compounds. The titanium oxo cluster are back oxidized in the presence of oxygen. This photochemical phenomenon is analyzed through the combined use of Electron Spin Resonance (ESR) and UV-visibte absorption spectroscopies. The photogenerated electrons are trapped as Ti(III) centers, while a concomitant oxidation of the adsorbed alcohol molecules occurs. This new microporous hybrid is a very promising candidate for applications in smart photonic devices, sensors, and catalysis