Surface defect controlled growth and high photocatalytic H 2 production efficiency of anatase TiO 2 nanosheets

Facet engineering of anatase TiO by controlling {001} exposure ratio has been the focus of numerous investigations to optimize the photocatalytic activity. In particular, an introduction of fluoride ions during the crystal growth has been demonstrated to be very effective and decisive in realizing t...

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Veröffentlicht in:ACS applied materials & interfaces 2019-10, Vol.11 (40), p.37256-37262
Hauptverfasser: Ruan, Luoyuan, Wang, Xinwei, Wang, Tongyao, Ren, Zhaohui, Chen, Ying, Zhao, Ruoyu, Zhou, Dikui, Fu, Gangjie, Li, Shi, Gao, Lina, Lu, Yunhao, Wang, Zhiyu, Tian, He, Kong, Xueqian, Han, Gaorong
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Sprache:eng
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Zusammenfassung:Facet engineering of anatase TiO by controlling {001} exposure ratio has been the focus of numerous investigations to optimize the photocatalytic activity. In particular, an introduction of fluoride ions during the crystal growth has been demonstrated to be very effective and decisive in realizing the facet exposure of the crystals. However, a key role of fluoride ions in stabilizing {001} exposure and improving subsequent photocatalytic activity of anatase TiO remains unclear up to date. Herein, a controlled thickness of anatase TiO nanosheets has been realized by introducing different amount of ethanol into a HF-acid-assisted hydrothermal reaction. The thinnest nanosheets with a thickness of ~2.9 nm were evaluated to have the highest H production rate of 41.04 mmol·h ·g under ultraviolet light irradiation, and the corresponding quantum efficiency was determined to be 41.6% (λ=365 nm). Moreover, it is proved for the first time that fluoride ions are bonded with Ti vacancies on {001} facets, and such defects are crucial for stabilizing the ultrathin nanosheets and improving their electron-hole separation, therefore leading to a highly efficient photocatalytivity. The findings offer an opportunity to engineer facets and functionality of anatase TiO by controlling surface defect.
ISSN:1944-8244
1944-8252
DOI:10.1021/acsami.9b11233