Generation of Photocurrents by Bis-aniline-Cross-Linked Pt Nanoparticle/Photosystem I Composites on Electrodes
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- 作者：Omer Yehezkeli ; Ofer I. Wilner ; Ran Tel-Vered ; Dan Roizman-Sade ; Rachel Nechushtai ; Itamar Willner
- 刊名：Journal of Physical Chemistry B
- 出版年：2010
- 出版时间：November 18, 2010
- 年：2010
- 卷：114
- 期：45
- 页码：14383-14388
- 全文大小：270K
- 年卷期：v.114,no.45(November 18, 2010)
- ISSN：1520-5207
文摘
Pt nanocrystals are implanted into photosystem I (PSI) by a photochemical reaction. The PSI with the associated Pt nanoclusters was modified with thioaniline and electropolymerized with thioaniline-functionalized Pt nanoparticles (NPs) to yield a bis-aniline-cross-linked PSI/Pt NPs composite. The alignment of the PSI with respect to the Pt NPs leads to effective charge separation and to generation of a photocurrent, (λ = 420 nm) = 2.6%, IPCE 0.35%. The bis-aniline units cross-linking the PSI/Pt NPs composite exhibit quasireversible redox features (E0′ = 0.05 V vs Ag/AgCl, at pH = 7.4). Biasing the electrode potential, E > 0.1 V vs SCE, results in the formation of the oxidized quinoid bis-aniline state that acts as an electron acceptor. At this applied potential, the bridges mediate the electron transfer to the electrode, resulting in a 10-fold higher photocurrent, as compared to the system that includes the reduced bis-aniline bridging units. Furthermore, the ferredoxin (Fd) electron relay was modified with thioaniline units and incorporated into the PSI/Pt NP composite during the electropolymerization process. The Fd bound to the matrix mediates the electron transfer toward the electrode and facilitates charge separation that results in enhanced generation of the photocurrent, (λ = 420 nm) = 3.8%, IPCE 0.5%.