Single nanocrystals of anatase-type TiO2 prepared from layered titanate nanosheets:: Formation mechanism and characterization of surface properties
Single nanocrystals of anatase-type TiO2 prepared from layered titanate nanosheets:: Formation mechanism and characterization of surface properties
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DOI：
10.1021/la701632t
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发表时间：
2007-11-06
期刊：
影响因子：
3.9
通讯作者：
Feng, Qi
中科院分区：
文献类型：
--
作者：
Wen, Puhong;Itoh, Hiroshi;Feng, Qi
通过水热处理层状钛酸盐纳米片胶体溶液，制备了具有船状、梳状、片状、叶状、方形、菱形和线状颗粒形态的锐钛矿型TiO2单纳米晶体。采用XRD、TEM、TG-DTA、BET比表面积、光催化活性、钌染料（N719）吸附等测试手段研究了TiO2纳米晶的形成反应和表面性质。结晶形态受反应温度、反应溶液pH值和去角质剂的控制。通过两种反应将钛酸盐纳米片转化为TiO2纳米晶体。一种是原位拓扑结构转化反应，另一种是表面溶解-沉积反应。原位拓扑结构转变反应形成的锐钛矿纳米晶保留了前驱体的片状颗粒形态，并优先暴露锐钛矿结构的（010）面。本研究制备的锐钛矿纳米晶体的晶体表面比标准锐钛矿纳米样品Ishihara ST-01样品具有更高的光催化活性和更高的钌染料吸附能力。结果表明，锐钛矿结构的（010）面具有较高的光催化活性和较高的钌染料吸附能力。
Anatase-type TiO2 single nanocrystals with boatlike, comblike, sheetlike, leaflike, quadrate, rhombic, and wirelike particle morphologies were prepared by hydrothermal treatment of a layered titanate nanosheet colloidal solution. The formation reactions and surface properties of the TiO2 nanocrystals were investigated using XRD, TEM, TG-DTA analyses, and measurements of BET specific surface area, photocatalytic activity, and ruthenium dye (N719) adsorption. The crystal morphology can be controlled by reaction temperature, pH value of reaction solution, and exfoliating agent. The titanate nanosheets were transformed to the TiO2 nanocrystals by two types of reactions. One is an in situ topotactic structural transformation reaction, and the other is a dissolution-deposition reaction on the surface. The anatase nanocrystals formed by the in situ topotactic structural transformation reaction retain the sheetlike particle morphology of the precursor, and they preferentially expose the (010) plane of anatase structure. The crystal surface of anatase nanocrystals prepared in this study showed higher photocatalytic activity and higher ruthenium dye adsorption capacity than did the Ishihara ST-01 sample, a standard anatase nanocrystal sample. The results indicated the (010) plane of the anatase structure has high photocatalytic activity and high ruthenium dye adsorption ability.