Photoelectrochemistry with Integrated Photosensitizer-Electron Acceptor and Au-Nanoparticle Arrays

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• 作者：Michal Lahav ; Vered Heleg-Shabtai ; Julian Wasserman ; Eugenii Katz ; Itamar Willner ; Heinz Dü ; rr ; Yi-Zhen Hu ; and Stefan H. Bossmann
• 刊名：Journal of the American Chemical Society
• 出版年：2000
• 出版时间：November 22, 2000
• 年：2000
• 卷：122
• 期：46
• 页码：11480 - 11487
• 全文大小：135K
• 年卷期：v.122,no.46(November 22, 2000)
• ISSN：1520-5126

文摘

Photosensitizer/electron acceptor molecular cross-linked Au-nanoparticle arrays are assembled onindium-doped tin oxide (ITO) electrodes by a layer-by-layer deposition process. A Ru(II)-tris-(2,2'-bipyridine)-cyclobis(paraquat-p-phenylene) catenane (1) or Zn(II)-protoporphyrin IX-bis(N-methyl-N'-undecanoate-4,4'-bipyridinium) (2) are used as molecular cross-linkers for the generation of Au-nanoparticle (13 ± 1 nm) arraysof a controlled number of layers. The Au-nanoparticle arrays are characterized by absorbance spectroscopyand by electrochemical means. The electrodes functionalized with 1- or 2-cross-linked Au-nanoparticle arraysare used in photoelectrochemical experiments. The resulting action spectra of the photocurrents follow theabsorbance spectra of the respective chromophores. Mechanistic studies indicate that the photocurrents originatefrom intramolecular electron-transfer quenching of the photoexcited state of the photosensitizer by the electronacceptor units, leading to the formation of intermediate redox species. The oxidized photoproduct oxidizes thesacrificial electron donor, Na₂EDTA, whereas the reduced bipyridinium radical cations transfer the electronsto the bulk electrode support.