Machida Masato, Mitsuyama Tomohiro, Ikeue Keita, Matsushima Shigenori, Arai Masao
Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, Kumamoto 860-8555, Japan.
J Phys Chem B. 2005 Apr 28;109(16):7801-6. doi: 10.1021/jp044833d.
The Dion-Jacobson series of triple-layered perovskite tantalates (MCa2Ta3O10, M = Cs, Na, H, and C6H13NH3) were synthesized to evaluate their photocatalytic activity for overall water splitting to evolve H2/O2 under UV irradiation. The photocatalytic activity was susceptible to the hydration of interlayer space. The hydrous Na phase exhibited much higher activity (H2: 308 micromol.h(-1)) compared to the anhydrous Cs phase (24 micromol.h(-1)) and the hydrous H phase (22 micromol.h(-1)) in the presence of 0.5 wt % Ni impregnated. H2O/D2O isotopic experiment suggested that the hydrated interlayer plays as an active site for water splitting, where the high mobility of water molecule in the interlayer should correlate with the total photocatalytic activity. The FLAPW electronic structure calculation demonstrated that the terminating oxygen site, O4, which faces to the interlayer space, contributes largely to the top of the valence band. Judging from comparison with the double-layered tantalates, MLaTa2O7, in our previous study, the contribution of terminating oxygen site to the band structure is supposed to depend on the number of perovskite layers.
合成了狄翁 - 雅各布森系列的三层钙钛矿钽酸盐（MCa2Ta3O10，M = Cs、Na、H和C6H13NH3），以评估它们在紫外光照射下对全分解水产生H2/O2的光催化活性。光催化活性对层间空间的水合作用敏感。在浸渍0.5 wt% Ni的情况下，含水的Na相表现出比无水Cs相（24 μmol·h(-1)）和含水H相（22 μmol·h(-1)）更高的活性（H2：308 μmol·h(-1)）。H2O/D2O同位素实验表明，水合层间充当了水分解的活性位点，其中层间水分子的高迁移率应与总的光催化活性相关。全势线性缀加平面波电子结构计算表明，面向层间空间的末端氧位点O4对价带顶有很大贡献。从与我们之前研究中的双层钽酸盐MLaTa2O7的比较来看，末端氧位点对能带结构的贡献应该取决于钙钛矿层的数量。
