The fabrication of well defined hierarchical structures of anatase TiO2 with a high percentage of reactive facets is of great importance and challenging. Hierarchically flower-like TiO2 superstructures (HFTS) self-assembled from anatase TiO2 nanosheets with exposed {001} facets (up to 87%) were synthesized by a simple alcohothermal strategy in a HF-H2O-C2H5OH mixed solution using titanate nanotubes as precursor. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy,and N2 adsorption-desorption isotherms. The photocatalytic activity was evaluated by the photocatalytic oxidation decomposition of acetone in air and methyl orange in aqueous solution under UV illumination. The photocatalytic activity of HFTS was much higher than that of commercial Degussa P25 and tabular-shaped anatase TiO2 obtained using pure water as the synthesis medium. The enhancement in photocatalytic activity was related to several factors, including the hierarchically porous structure, exposed {001 } facets, and increased light harvesting ability. The HFTS was also of interest for use in solar cells, photocatalytic H2 production, optoelectronic devices, sensors, and catalysis.%以钛酸盐纳米管为前驱体,在HF-H2O-C2H5OH的混合溶液中,采用一种简单的醇热方法合成了具有87%暴露{001}面的TiO2纳米片自组装形成的分等级花状TiO2超结构.运用X射线衍射、扫描电镜、透射电镜和N2吸附-脱附等方法对样品进行了表征,并在紫外光照射下于空气和溶液中分别考察了其光催化降解丙酮和甲基橙反应活性.结果表明,这种分等级花状结构TiO2的光催化活性比商业P25和在纯水中制备得到的片状锐钛矿TiO2的光活性高得多.这主要是由于该样品具有分等级的多孔结构,暴露的{001}晶面和增强的光吸收能力.这种分等级花状TiO2超结构在太阳能电池、光催化产氢、光电子器件、传感器和催化方面也具有巨大的应用前景.
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