Abe Ryu, Higashi Masanobu, Sayama Kazuhiro, Abe Yoshimoto, Sugihara Hideki
National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
J Phys Chem B. 2006 Feb 9;110(5):2219-26. doi: 10.1021/jp0552933.
The photocatalytic activities of R3MO7 and R2Ti2O7 (R=Y, Gd, La; M=Nb, Ta) strongly depended on the crystal structure. Overall, photocatalytic water splitting into H2 and O2 proceeded over La3TaO7 and La3NbO7, which have an orthorhombic weberite structure, Y2Ti2O7 and Gd2Ti2O7, which have a cubic pyrochlore structure, and La2Ti2O7, which has a monoclinic perovskite structure. All of these materials are composed of a network of corner-shared octahedral units of metal cations (TaO6, NbO6, or TiO6); materials without such a network were inactive. The octahedral network certainly increased the mobility of electrons and holes, thereby enhancing photocatalytic activity.
R3MO7和R2Ti2O7（R = Y、Gd、La；M = Nb、Ta）的光催化活性强烈依赖于晶体结构。总体而言，光催化水分解生成H2和O2的反应在具有斜方钡解石结构的La3TaO7和La3NbO7、具有立方烧绿石结构的Y2Ti2O7和Gd2Ti2O7以及具有单斜钙钛矿结构的La2Ti2O7上进行。所有这些材料均由金属阳离子（TaO6、NbO6或TiO6）的角共享八面体单元网络组成；没有这种网络的材料没有活性。八面体网络肯定增加了电子和空穴的迁移率，从而提高了光催化活性。
