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AuthorLiu, Yong
AuthorLuo, Yongfeng
AuthorElzatahry, Ahmed A.
AuthorLuo, Wei
AuthorChe, Renchao
AuthorFan, Jianwei
AuthorLan, Kun
AuthorAl-Enizi, Abdullah M.
AuthorSun, Zhenkun
AuthorLi, Bin
AuthorLiu, Zhengwang
AuthorShen, Dengke
AuthorLing, Yun
AuthorWang, Chun
AuthorWang, Jingxiu
AuthorGao, Wenjun
AuthorYao, Chi
AuthorYuan, Kaiping
AuthorPeng, Huisheng
AuthorTang, Yun
AuthorDeng, Yonghui
AuthorZheng, Gengfeng
AuthorZhou, Gang
AuthorZhao, Dongyuan
Available date2016-10-23T07:03:40Z
Publication Date2015-10-28
Publication NameACS Central Scienceen_US
Identifierhttp://dx.doi.org/10.1021/acscentsci.5b00256
CitationLiu Y, Luo Y, Elzatahry AA, et al. Mesoporous TiO2 Mesocrystals: Remarkable Defects-Induced Crystallite-Interface Reactivity and Their in Situ Conversion to Single Crystals. ACS Central Science. 2015;1(7):400-408.
ISSN2374-7951
URIhttp://hdl.handle.net/10576/4912
AbstractOriented self-assembly between inorganic nanocrystals and surfactants is emerging as a route for obtaining new mesocrystalline semiconductors. However, the actual synthesis of mesoporous semiconductor mesocrystals with abundant surface sites is extremely difficult, and the corresponding new physical and chemical properties arising from such an intrinsic porous mesocrystalline nature, which is of fundamental importance for designing high-efficiency nanostructured devices, have been rarely explored and poorly understood. Herein, we report a simple evaporation-driven oriented assembly method to grow unprecedented olive-shaped mesoporous TiO2 mesocrystals (FDU-19) self-organized by ultrathin flake-like anatase nanocrystals (∼8 nm in thickness). The mesoporous mesocrystals FDU-19 exhibit an ultrahigh surface area (∼189 m2/g), large internal pore volume (0.56 cm3/g), and abundant defects (oxygen vacancies or unsaturated Ti3+ sites), inducing remarkable crystallite-interface reactivity. It is found that the mesocrystals FDU-19 can be easily fused in situ into mesoporous anatase single crystals (SC-FDU-19) by annealing in air. More significantly, by annealing in a vacuum (∼4.0 × 10–5 Pa), the mesocrystals experience an abrupt three-dimensional to two-dimensional structural transformation to form ultrathin anatase single-crystal nanosheets (NS-FDU-19, ∼8 nm in thickness) dominated by nearly 90% exposed reactive (001) facets. The balance between attraction and electrostatic repulsion is proposed to determine the resulting geometry and dimensionality. Dye-sensitized solar cells based on FDU-19 and SC-FDU-19 samples show ultrahigh photoconversion efficiencies of up to 11.6% and 11.3%, respectively, which are largely attributed to their intrinsic single-crystal nature as well as high porosity. This work gives new understanding of physical and chemical properties of mesoporous semiconductor mesocrystals and opens up a new pathway for designing various single-crystal semiconductors with desired mesostructures for applications in catalysis, sensors, drug delivery, optical devices, etc.
SponsorState Key Basic Research Program of China (2013CB934104 and 2012CB224805), the National Science Foundation (21210004) and Science & Technology Commission of Shanghai Municipality (14JC1400700), Shanghai Leading Academic Discipline Project (B108), and Deanship of Scientific Research, KSU-The International Highly Cited Research Group program (IHCRG#14-102). Y.L. also acknowledges the Interdisciplinary Outstanding Doctoral Research Funding of Fudan University (EZH2203302/001).
Languageen
PublisherAmerican Chemical Society
SubjectOrdered superstructures
SubjectCrystallization
SubjectEvaporation
TitleMesoporous TiO2 Mesocrystals: Remarkable Defects-Induced Crystallite-Interface Reactivity and Their in Situ Conversion to Single Crystals
TypeArticle
Pagination400-408
Issue Number7
Volume Number1


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