Accumulative electron transfer: Multiple charge separation in artificial photosynthesis

Susanne Karlsson, Julien Boixel, Yann Pellegrin, Errol Blart, Hans Christian Becker, Fabrice Odobel, Leif Hammarström

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

To achieve artificial photosynthesis it is necessary to couple the single-electron event of photoinduced charge separation with the multi-electron reactions of fuel formation and water splitting. Therefore, several rounds of light-induced charge separation are required to accumulate enough redox equivalents at the catalytic sites for the target chemistry to occur, without any sacrificial donors or acceptors other than the catalytic substrates. Herein, we discuss the challenges of such accumulative electron transfer in molecular systems. We present a series of closely related systems base on a Ru II-polypyridine photosensitizer with appended triaryl-amine or oligo-triaryl-amine donors, linked to nanoporous TiO 2 as the acceptor. One of the systems, based on dye 4, shows efficient accumulative electron transfer in high overall yield resulting in the formation of a two-electron charge-separated state upon successive excitation by two photons. In contrast, the other systems do not show accumulative electron transfer because of different competing reactions. This illustrates the difficulties in designing successful systems for this still largely unexplored type of reaction scheme.

Original languageEnglish
Pages (from-to)233-252
Number of pages20
JournalFaraday Discussions
Volume155
DOIs
Publication statusPublished - Feb 21 2012

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

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