Mesocrystalline TiO_(2) nanosheet arrays with exposed {001} facets: Synthesis via topotactic transformation and applications in dye-sensitized solar cells  

作　　者：Yanhe Zhang Jinguang Cai Yurong Ma Limin Qi 

机构地区：[1]Beijing National Laboratory for Molecular Sciences(BNLMS),State Key Laboratory for Structural Chemistry of Unstable and Stable Species,College of Chemistry,Peking University,Beijing 100871,China

出　　处：《Nano Research》2017年第8期2610-2625,共16页纳米研究(英文版)

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.21473004 and 21673007);the National Basic Research Program of China(No.2013CB932601).

摘　　要：A facile,fluorine-free approach for synthesizing vertically aligned arrays of mesocrystaUine anatase TiO_(2) nanosheets with highly exposed{001}facets was developed through topotactic transformation.Unique mesocrystalline{001}-faceted TiO_(2) nanosheet arrays vertically aligned on conductive fluorine-doped tin oxide glass were realized through topotactic conversion from single-crystalline precursor nanosheet arrays based on lattice matching between the precursor and the anatase crystals.The morphology and microstructure of the{001}-faceted TiO_(2) nanosheets could be readily modulated by changing the reactant concentration and annealing temperature.Owing to enhanced dye adsorption,reduced charge recombination,and enhanced light scattering arising from the exposed{001}facets,in addition to the advantageous features of low-dimensional structure arrays(e.g.,fast electron transport and efficient charge collection),the obtained TiO_(2) nanosheet arrays exhibited superior performance when they were used as anodes for dye-sensitized solar cells(DSSCs).Particularly,{001}-faceted TiO_(2) nanosheet arrays-15μm long annealed at 500℃showed a power conversion efficiency of 7.51%.Furthermore,a remarkable efficiency of 8.85%was achieved for a DSSC based on doubleqayered TiO_(2) nanosheet arrays-35μm long,which were prepared by conversion from the precursor nanoarrays produced via secondary hydrothermal growth.

关 键 词：titanium dioxide NANOSHEETS {001}facets nanostructure arrays dye-sensitized solar cells MESOCRYSTALS 

分 类 号：TN958[电子电信—信号与信息处理] TM914.4[电子电信—信息与通信工程]