Teramura Kentaro, Maeda Kazuhiko, Saito Takafumi, Takata Tsuyoshi, Saito Nobuo, Inoue Yasunobu, Domen Kazunari
Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Phys Chem B. 2005 Nov 24;109(46):21915-21. doi: 10.1021/jp054313y.
The formation and structural characteristics of Ru species applied as a cocatalyst on (Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)()) are examined by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. RuO(2) is an effective cocatalyst that enhances the activity of (Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)()) for overall water splitting under visible-light irradiation. The highest photocatalytic activity is obtained for a sample loaded with 5.0 wt % RuO(2) from an Ru(3)(CO)(12) precursor followed by calcination at 623 K. Calcination is shown to cause the decomposition of initial Ru(3)(CO)(12) on the (Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)()) surface (373 K) to form Ru(IV) species (423 K). Amorphous RuO(2) nanoclusters are then formed by an agglomeration of finer particles (523 K), and the nanoclusters finally crystallize (623 K) to provide the highest catalytic activity. The enhancement of catalytic activity by Ru loading from Ru(3)(CO)(12) is thus shown to be dependent on the formation of crystalline RuO(2) nanoparticles with optimal size and coverage.
通过扫描电子显微镜、X射线光电子能谱和X射线吸收光谱研究了用作（Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)())助催化剂的Ru物种的形成及其结构特征。RuO₂是一种有效的助催化剂，可增强（Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)())在可见光照射下整体水分解的活性。以Ru(3)(CO)(12)前驱体负载5.0 wt% RuO₂并在623 K下煅烧的样品获得了最高的光催化活性。结果表明，煅烧会导致初始Ru(3)(CO)(12)在（Ga(1)(-)(x)()Zn(x)())(N(1)(-)(x)()O(x)())表面（373 K）分解形成Ru(IV)物种（423 K）。然后通过更细颗粒的团聚（523 K）形成非晶态RuO₂纳米团簇，纳米团簇最终结晶（623 K）以提供最高的催化活性。因此，由Ru(3)(CO)(12)负载Ru导致的催化活性增强取决于具有最佳尺寸和覆盖率的结晶RuO₂纳米颗粒的形成。
