Extremely stable photoinduced charge separation in a colloidal system composed of semiconducting niobate and clay nanosheets.
Extremely stable photoinduced charge separation in a colloidal system composed of semiconducting niobate and clay nanosheets.
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DOI：
10.1002/anie.200604483
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发表时间：
2007-05
影响因子：
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通讯作者：
N. Miyamoto;Yoshimi Yamada;S. Koizumi;T. Nakato
中科院分区：
文献类型：
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作者：
N. Miyamoto;Yoshimi Yamada;S. Koizumi;T. Nakato
胶体半导体颗粒因其在光能转换和光催化方面的应用而受到研究。[1]半导体颗粒的带隙光激发产生的电子和空穴通过随后的界面电子转移至受体和供体分子而分离。电荷分离态的稳定是控制半导体颗粒光激发引起的光化学反应的关键。受体和施主物质的空间分离可以通过抑制反向电子转移来有效地稳定电荷分离态。异质介质，如胶束和囊泡，已用于此类目的；[2]例如，通过使用囊泡、[3]微乳液、[4]和SiO2颗粒[5]作为异质介质，实现了半导体颗粒与受体或敏化剂分子之间的光致电荷分离。然而，在这些胶体系统中，光生电荷分离态的寿命仍然很短（寿命只有几分钟）。将受体和供体成分结合到纳米结构固体中，例如层状[6, 7]和多孔材料[8]，可以有效稳定电荷分离状态（寿命长达几个小时）。然而，固体系统有一个缺点，即难以被光和分子穿透。另一个缺点是储存光能的电荷分离产物不能轻易进行进一步的反应。
Colloidal semiconductor particles have been investigated because of their applications in photoenergy conversion and photocatalysis.[1] Electrons and holes generated upon bandgap photoexcitation of the semiconductor particles are separated by subsequent interfacial electron transfer to acceptor and donor molecules. The stabilization of the charge-separated state is key for controlling the photochemical reactions induced by photoexcitation of the semiconductor particles.The spatial separation of the acceptor and donor species can be used effectively to stabilize the charge-separated state by suppressing back electron transfer. Heterogeneous media, such as micelles and vesicles, have been utilized for such purposes;[2] for example, the photoinduced charge separation between semiconducting particles and acceptor or sensitizer molecules has been achieved by using vesicles,[3] microemulsions,[4] and SiO2 particles [5] as the heterogeneous media. However, in these colloidal systems the photogenerated charge-separated states are still short-lived (with lifetimes of only a few minutes). The incorporation of acceptor and donor components into nanostructured solids, such as layered [6, 7] and porous materials,[8] stabilizes effectively the chargeseparated state (with lifetimes of up to several hours). Nevertheless, solid systems have a drawback regarding the difficulty of being penetrated by both light and molecules. Another disadvantage is that the charge-separated products which store the photoenergy cannot undergo further reactions easily.