Enhancing the Photocatalytic Activity of Anatase TiO2 by Improving the Specific Facet-Induced Spontaneous Separation of Photogenerated Electrons and Holes

• Published in: Chemistry, an Asian journal an Asian journal, 2013-01, Vol.8 (1), p.282-289
• Main Authors: Liu, Chang, Han, Xiguang, Xie, Shuifen, Kuang, Qin, Wang, Xue, Jin, Mingshang, Xie, Zhaoxiong, Zheng, Lansun
• Format: Article
• Language: English
• Subjects: Chemistry; hydrogen evolution; Nanocrystals; nanostructures; Photocatalysis; surface chemistry; titanium
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.201200886

Recently, it has been proven that directional flow of photogenerated charge carriers occurs on specific facets of TiO2 nanocrystals. Herein, we demonstrate that the photocatalytic activity of anatase TiO2 nanocrystals in both photoreduction and photooxidation processes can be enhanced by selectively depositing Pt nanoparticles on the {101} facets, which strengthens spontaneously surface‐induced separation between photogenerated electrons and holes in the photocatalysis process. An optimal ratio of the oxidative {001} facets to the reductive {101} facets exists with regard to the photocatalysis of the faceted TiO2 nanocrystals, and this is crucial for balancing the recombination and redox reaction rates of photogenerated electrons and holes. The present work might help us gain deeper insight into the relation between the specific surface of semiconductor photocatalysts and their photocatalytic activities and provides us with a new route to design photocatalysts with high photocatalytic activity. Trial separation: Selectively depositing Pt nanoparticles on the {101} facets is effective in enhancing the photocatalytic activity of anatase TiO2 nanocrystals by improving the spontaneous separation efficiency of photogenerated electrons and holes (see figure). An optimal ratio of the oxidative {001} facets to the reductive {101} facets exists with regard to the photocatalytic activities.