Takeda Hiroyuki, Ohashi Masataka, Goto Yasutomo, Ohsuna Tetsu, Tani Takao, Inagaki Shinji
Toyota Central R&D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); JST/CREST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Present address: Tokyo Institute of Technology, 2-12-1-NE-2, O-okayama, Meguro-ku, Tokyo 152-8551 (Japan).
Chemistry. 2014 Jul 14;20(29):9130-6. doi: 10.1002/chem.201302815. Epub 2014 May 30.
An organic-based photocatalysis system for water oxidation, with visible-light harvesting antennae, was constructed using periodic mesoporous organosilica (PMO). PMO containing acridone groups in the framework (Acd-PMO), a visible-light harvesting antenna, was supported with [Ru(II)(bpy)3(2+)] complex (bpy = 2,2'-bipyridyl) coupled with iridium oxide (IrO(x)) particles in the mesochannels as photosensitizer and catalyst, respectively. Acd-PMO absorbed visible light and funneled the light energy into the Ru complex in the mesochannels through excitation energy transfer. The excited state of Ru complex is oxidatively quenched by a sacrificial oxidant (Na2S2O8) to form Ru(3+) species. The Ru(3+) species extracts an electron from IrO(x) to oxidize water for oxygen production. The reaction quantum yield was 0.34 %, which was improved to 0.68 or 1.2 % by the modifications of PMO. A unique sequence of reactions mimicking natural photosystem II, 1) light-harvesting, 2) charge separation, and 3) oxygen generation, were realized for the first time by using the light-harvesting PMO.
利用周期性介孔有机硅（PMO）构建了一种基于有机的光催化水氧化体系，该体系带有可见光捕获天线。在框架中含有吖啶酮基团的PMO（Acd-PMO）作为可见光捕获天线，在介孔通道中分别负载[Ru(II)(bpy)3(2+)]配合物（bpy = 2,2'-联吡啶）和氧化铱（IrO(x)）颗粒作为光敏剂和催化剂。Acd-PMO吸收可见光，并通过激发能量转移将光能输送到介孔通道中的Ru配合物中。Ru配合物的激发态被牺牲性氧化剂（Na2S2O8）氧化淬灭，形成Ru(3+)物种。Ru(3+)物种从IrO(x)中提取一个电子以氧化水来产生氧气。反应量子产率为0.34 %，通过对PMO进行改性，该产率提高到了0.68 %或1.2 %。首次利用这种光捕获PMO实现了模拟天然光系统II的独特反应序列：1）光捕获、2）电荷分离和3）氧气生成。
