Visible light-driven water oxidation using a covalently-linked molecular catalyst-sensitizer dyad assembled on a TiO(2) electrode.
Visible light-driven water oxidation using a covalently-linked molecular catalyst-sensitizer dyad assembled on a TiO(2) electrode.
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DOI：
10.1039/c5sc03669k
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发表时间：
2016-02-01
期刊：
影响因子：
8.4
通讯作者：
Imahori H
中科院分区：
文献类型：
--
作者：
Yamamoto M;Wang L;Li F;Fukushima T;Tanaka K;Sun L;Imahori H
卟啉作为敏化剂和钌配合物作为水氧化催化剂（WOC）的组合有希望开发高效的分子人工光合系统。卟啉作为敏化剂和钌配合物作为水氧化催化剂（WOC）的组合有希望开发高效的分子人工光合系统。将共价键合的钨酸锌卟啉（ZnP）敏化剂组装在TiO 2电极上，用于可见光驱动水的氧化.发现与具有单独WOC和ZnP的简单组合以及仅具有ZnP的参考系统相比，水氧化活性得到改善，证明共价连接方法优于非共价连接方法。更重要的是，通过由可见光触发的矢量多步电子转移，染料敏化光电化学电池（DSPEC）在可见光区实现了比传统的基于铼的敏化剂的DSPEC更广泛的PEC响应。在单色光照射和-0.2 V vs. NHE的外部偏压下，424 nm处的初始入射光子-电流效率为18%，564 nm处为6.4%。通过共价键从WOC到敏化剂的光生自由基阳离子的快速电子转移可以抑制不期望的电荷复合，实现水氧化的适度性能。在DSPEC操作之前和之后的光阳极的X射线光电子能谱分析表明，大部分的钌物种存在于较高的氧化态，这意味着ZnP部分用于进一步氧化在光阳极的中间体钌物种的氧化电位不足至少是该系统的瓶颈。
The combination of porphyrin as a sensitizer and a ruthenium complex as a water oxidation catalyst (WOC) is promising to exploit highly efficient molecular artificial photosynthetic systems. The combination of porphyrin as a sensitizer and a ruthenium complex as a water oxidation catalyst (WOC) is promising to exploit highly efficient molecular artificial photosynthetic systems. A covalently-linked ruthenium-based WOC–zinc porphyrin (ZnP) sensitizer dyad was assembled on a TiO2 electrode for visible-light driven water oxidation. The water oxidation activity was found to be improved in comparison to the reference systems with the simple combination of the individual WOC and ZnP as well as with ZnP solely, demonstrating the advantage of the covalent linking approach over the non-covalent one. More importantly, via vectorial multi-step electron transfer triggered by visible light, the dye-sensitized photoelectrochemical cell (DSPEC) achieved a broader PEC response in the visible region than DSPECs with conventional ruthenium-based sensitizers. Initial incident photon-to-current efficiencies of 18% at 424 nm and 6.4% at 564 nm were attained under monochromatic illumination and an external bias of –0.2 V vs. NHE. Fast electron transfer from the WOC to the photogenerated radical cation of the sensitizer through the covalent linkage may suppress undesirable charge recombination, realizing the moderate performance of water oxidation. X-ray photoelectron spectroscopic analysis of the photoanodes before and after the DSPEC operation suggested that most of the ruthenium species exist at higher oxidation states, implying that the insufficient oxidation potential of the ZnP moiety for further oxidizing the intermediate ruthenium species at the photoanode is at least the bottleneck of the system.
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影响因子：
16.6
作者：
Chen, Jun;Wagner, Pawel;Swiegers, Gerhard F.
通讯作者：
Swiegers, Gerhard F.
影响因子：
15
作者：
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Hammarström, L
影响因子：
15
作者：
Barder, TE;Walker, SD;Buchwald, SL
通讯作者：
Buchwald, SL
影响因子：
3.3
作者：
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通讯作者：
Durrant, JR
影响因子：
15
作者：
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通讯作者：
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