异形复层结构TiO_2纳米棒薄膜的水热合成及性能(英文)

Hydrothermal Synthesis of a Dysmorphic Double Layer Structure TiO_2 Nanorod Films and Its Properties

本文采用水热反应法．通过改变合成条件，经XRD和FESEM表征，证实合成了四方金红石相异形复层f阵列一团簇）结构的TiO2薄膜。合成薄膜的下层是TiO2的阵列，上层是团簇状的TiO2。并且构成阵列和团簇的每个方柱又由多根纳米棒（25．65nm）组成。上层团簇的生成量和厚度可以通过改变反应物的初始浓度、反应时间和生长基片的角度进行调控。将这种异形复层结构薄膜试用于染料敏化太阳能电池（DSSC）光阳极．发现其光电转化效率比单层阵列TiO2薄膜提高了2．6倍。由此表明TiO2这种以纳米棒为单元结构的异形复层薄膜．上层团簇结构有利于产生采光作用以及吸附微粒的作用．下层阵列结构有利于载流子的定向快速传输．其复合结构的形成。致使光电转换效果明显提高。

A type of double layer （array-cluster）TiO2 films were prepared with mixed solution of hydrochloric acid and tetrabutyl titanate （TBOT） by a hydrothermal method at specific reaction condition. It was found that the TiOa films on the substrate has a two-layer structure and has the tetragonal rutile phase observed from the field emission scaning electron microscopy （FESEM） and the X-ray diffraction （XRD）. Moreover, the subjacent layer of the two-layer structure were TiO2 rods array, while the supernatant layer was TiO2 rods clusters, and microscopic structure of these rods all are made of smaller TiO~ nanorods （25~65 nm）. This two-layer structure of TiO2 films can favors to acquiring more light and adsorbing more dye, and could provide a fast circulation channel for photon-generated electrons. The thickness of this type of TiO2 films in supernatant layer can be varied by changing initial reactant concentration, growth time or substrate placed angles. And without any modification treatment, a light-to-electricity conversion effciency of DSSC with TiO2 nanorod array-cluster films can enhance 2.6 time in comparison with only TiO2 nanorod array films.