Spacer effects in metal-free organic dyes for visible-light-driven dye-sensitized photocatalytic hydrogen production
Spacer effects in metal-free organic dyes for visible-light-driven dye-sensitized photocatalytic hydrogen production
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DOI：
10.1039/c4ta02720e
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发表时间：
2014-08-28
影响因子：
11.9
通讯作者：
Ishihara, Tatsumi
中科院分区：
文献类型：
--
作者：
Watanabe, Motonori;Hagiwara, Hidehisa;Ishihara, Tatsumi
合成了含苯并[B]吩噻嗪的无金属有机染料，并将其有效地用于染料敏化可见光催化制氢。当在供体和锚部分之间插入许多π共轭桥作为间隔物时，材料表现出高稳定性和氢产生。以三乙醇胺为牺牲剂，研究了TiO 2/染料/Pt结构的光催化制氢性能。化合物染料3在给体和受体之间具有最长的间隔基，在本研究所研究的系列中表现出最好的产氢性能。其在420 nm处的转换数（TON）为4460，16 h后的转换频率为278，光量子效率为1.65%。此外，它表现出最长的电子注入寿命，因为它的配位结构被认为是垂直的TiO 2表面上的理论计算。另一方面，染料1显示出最低的氢产生性能，TON为483并且电子注入寿命非常短。计算结果证实了这一观察结果，它显示了1与单齿配合的染料相对于TiO 2表面的说谎的几何形状。该研究为开发无金属有机染料敏化光催化分解水提供了一个很好的策略。
Metal-free organic dyes containing benzo[b]phenothiazine were synthesized and effectively used for dye-sensitized visible-light-driven photocatalytic hydrogen production. The materials exhibited high stability and hydrogen production when numerous pi-conjugated bridges were inserted as spacers between the donor and the anchor moiety. Photocatalytic hydrogen production was investigated in a TiO2/dye/Pt structure using triethanolamine as the sacrificial reagent. Compound dye 3, which had the longest spacer between the donor and the acceptor, exhibited the best hydrogen production performance of the series examined in this study. It displayed a turnover number (TON) of 4460, a turnover frequency of 278 after 16 h, and a photo-quantum efficiency of 1.65% at 420 nm. Furthermore, it showed the longest electron injection lifetime because its coordination structure was considered to be vertically standing on the TiO2 surface by theoretical calculations. On the other hand, dye 1 showed the lowest hydrogen production performance with a TON of 483 and very short electron injection lifetime. This observation is confirmed by the computation results, which showed the lying geometry of 1 with monodentate coordination of the dye with respect to the TiO2 surface. This spacer effectproperty relationship study may provide a good strategy for the development of metal-free organic dyes for dye-sensitized photocatalytic water splitting.