金红石型TiO_2/锐钛矿型TiO_2/SiO_2三元复合薄膜的合成

Synthesis of Rutile TiO_2/Anatase TiO_2/SiO_2 Ternary Composite Films

采用水热法,以钛酸正丁酯为初始原料,在FTO基底上沉积了金红石型TiO2纳米棒阵列,然后利用锐钛矿型TiO2纳米粒子及无定形SiO2对纳米棒进行了表面修饰,获得金红石型TiO2/锐钛矿型TiO2/SiO2三元复合薄膜。扫描电镜及X射线衍射分析结果表明,在FTO表面上沉积的TiO2为金红石型单晶纳米棒,其尺寸随反应时间的增加而增大。电化学测试结果表明,随着纳米棒尺寸的增大,相应复合薄膜的电化学反应电荷转移阻力增大。2种TiO2晶型混合引起的电子-空穴分离效应及混合的均匀程度直接影响到复合薄膜的光催化活性。水热反应7h得到的纳米棒阵列相应的复合薄膜显示了较好的电化学性能及光催化活性。

Single - crystalline rutile nanorod array was deposited on the surface of FTO using tetrahutyl titanate as titanium source by hydrothermal method. Then ternary composite films consisting of rutile TiO2, anatase TiO2 and SiO2 were prepared through a modification of rutile nanorods with anatase TiO2 nanoparticles and amorphous SiO2. SEM and XRD results indicate that the deposited TiO2 on FTO surface is single - crystal rutile nanorod, the size of which increases with the increasing of hydrothermal reaction time. The results of electrochemical property measurement show that resistance of carrier transport in film increases as the size of nanorod is increased. An electron - hole separation due to the mixing of anatase and rutile and a homogenous microstructure are the keys to achieve high photocatalytic activity of composite film. The composite film, prepared with single - crystalline nanorods with hydrothermal reaction time of 7 h, shows relatively higher electrochemical properties and photocatalytic activity.