Improving Photocatalytic H2 Evolution of TiO2 via Formation of {001}鈥搟010} Quasi-Heterojunctions

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• 作者：Danping Wang ; Pushkar Kanhere ; Mingjie Li ; Qiuling Tay ; Yuxin Tang ; Yizhong Huang ; Tze Chien Sum ; Nripan Mathews ; Thirumany Sritharan ; Zhong Chen
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：November 7, 2013
• 年：2013
• 卷：117
• 期：44
• 页码：22894-22902
• 全文大小：649K
• 年卷期：v.117,no.44(November 7, 2013)
• ISSN：1932-7455

文摘

The coexistence of low-index facets with a highly photoactive {001} facet in anatase TiO₂ nanocrystals has been recently found beneficial to enhance the photocatalytic performance of TiO₂ via a synergistic effect. In this paper, this synergistic effect has been further extended from a single crystal to interconnected nanocrystals with dominating {001} or {010} facet in intact hierarchical TiO₂ nanostrucutre. The particles synthesized at the optimal condition showed outstanding photocatalytic hydrogen production of 364.2 渭mol路g^鈥?路h^鈥?, which is about four times as much as that of commercial P25 (96.5 渭mol路g^鈥?路h^鈥?). Femtosecond transient spectroscopy and density functional theory (DFT) study indicates that effective electron鈥揾ole separation takes place within these nanostructures. This new prototype of synergy, which we denote as quasi-heterojunctions, shows that enhanced photocatalytic performance could be derived in the same anatase phase by synthesizing appropriate faceted nanostructures. This work provides a new dimension to facet engineering of TiO₂ and other semiconductor photocatalysts.