Rutile Crystallites Isolated from Degussa (Evonik) P25 TiO2: Highly Efficient Photocatalyst for Chemoselective Hydrogenation of Nitroaromatics
Rutile Crystallites Isolated from Degussa (Evonik) P25 TiO2: Highly Efficient Photocatalyst for Chemoselective Hydrogenation of Nitroaromatics
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DOI：
10.1021/cs400532p
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发表时间：
2013-09
期刊：
影响因子：
12.9
通讯作者：
Yasuhiro Shiraishi;H. Hirakawa;Yoshiki Togawa;Yoshitsune Sugano;S. Ichikawa;T. Hirai
中科院分区：
文献类型：
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作者：
Yasuhiro Shiraishi;H. Hirakawa;Yoshiki Togawa;Yoshitsune Sugano;S. Ichikawa;T. Hirai
我们报道了用氢氟酸处理从Degussa(Evonik)P25 TiO2光催化剂中分离出的金红石微晶，它是一种高效的硝基芳烃加氢光催化剂。以乙醇为氢源，对分离的金红石粒子进行光照射(λ>；300 nm)，成功地促进了硝基芳香族化合物的化学选择加氢生成苯胺，其活性高于商业金红石型二氧化钛。孤立的金红石颗粒的高活性是由于颗粒上的结构缺陷(氧空位)的特殊分布所致。这些颗粒含有数量相对较少的内部缺陷，充当光生电子(e-)和正空穴(h+)对的复合中心，以及相对大量的表面缺陷，充当硝基芳烃的还原中心。因此，孤立粒子的光激发促进了e-和h+之间的有效电荷分离，并促进了吸附的硝基芳烃的快速还原。
We report that the rutile crystallites, isolated from Degussa (Evonik) P25 TiO2 by a hydrofluoric acid treatment, behave as a highly efficient photocatalyst for hydrogenation of nitroaromatics. Photoirradiation (λ >300 nm) of the isolated rutile particles with alcohol as a hydrogen source successfully promotes chemoselective hydrogenation of nitroaromatics to anilines, with an activity higher than that of commercially available rutile TiO2. The high activity of the isolated rutile particles is due to the specific distribution of structural defects (oxygen vacancy sites) on the particles. These particles contain a relatively small number of inner defects behaving as recombination centers for photoformed electron (e–) and positive hole (h+) pairs, and a relatively large number of surface defects behaving as reduction sites for nitroaromatics. Photoexcitation of the isolated particles therefore promotes efficient charge separation between e– and h+, and facilitates rapid reduction of nitroaromatics adsorbed ...