Rutile Crystallites Isolated from Degussa (Evonik) P25 TiO<sub>2</sub>: Highly Efficient Photocatalyst for Chemoselective Hydrogenation of Nitroaromatics Yasuhiro Shiraishi Hiroaki Hirakawa Yoshiki Togawa Yoshitsune Sugano Satoshi Ichikawa Takayuki Hirai 10.1021/cs400532p.s001 https://acs.figshare.com/articles/journal_contribution/Rutile_Crystallites_Isolated_from_Degussa_Evonik_P25_TiO_sub_2_sub_Highly_Efficient_Photocatalyst_for_Chemoselective_Hydrogenation_of_Nitroaromatics/2369944 We report that the rutile crystallites, isolated from Degussa (Evonik) P25 TiO<sub>2</sub> 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 TiO<sub>2</sub>. 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<sup>–</sup>) and positive hole (h<sup>+</sup>) 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<sup>–</sup> and h<sup>+</sup>, and facilitates rapid reduction of nitroaromatics adsorbed on the surface defects. This thus results in very high hydrogenation activity on the rutile particles isolated from P25 TiO<sub>2</sub>. 2016-02-18 17:58:36 hydrofluoric acid treatment rutile TiO 2. hydrogenation surface defects P 25 TiO 2 nitroaromatic rutile particles oxygen vacancy sites