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Low Temperature Synthesis of Large‐Size Anatase TiO 2 Nanosheets with Enhanced Photocatalytic Activities
Author(s) -
Tang Xiao,
Chu Wanyi,
Qian Jueshi,
Lin Jingcheng,
Cao Guozhong
Publication year - 2017
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201701964
Subject(s) - photocatalysis , anatase , materials science , nanostructure , nanotechnology , chemical engineering , absorption (acoustics) , ostwald ripening , aqueous solution , irradiation , microstructure , catalysis , chemistry , composite material , organic chemistry , nuclear physics , engineering , physics
TiO 2 nanosheets have continuously been intriguing due to their high surface activities as photocatalyst but still challenging to synthesis large‐scale 2D nanostructures. A special microstructure evolution of TiO 2 , ripening in aqueous solution at low temperature (≈4 °C), is found for the first time, i.e., from the initial aperiodic atom‐networks gradually into low crystallized continuous spongy structure with small crystal facets and ultimately forming large‐size anatase nanosheets with exposed (101) and (200) facets. Based on this finding, the synthesized anatase TiO 2 nanosheets possess monodispersed large‐scale 2D nanostructure so as to exhibit appreciable quantum size effects and remarkable enhanced optical absorption capacity. Using photocatalytic reduction of Cr (VI) to Cr (III) as the probe reaction to evaluate photocatalytic activities of the TiO 2 nanosheets, the reductivity of Cr (VI) achieves 99.8% in 15 min under irradiation of 200–800 nm light. At the same time, an in situ Cr (III)‐doping occurs spontaneously and triggers pronounced visible light driven photocatalysis, reducing 99% of Cr (VI) in 100 min under irradiation of 400–800 nm light.