Sensitizer-catalyst assemblies for water oxidation

Lei Wang, Mohammad Mirmohades, Allison Brown, Lele Duan, Fusheng Li, Quentin Daniel, Reiner Lomoth, Licheng Sun, Leif Hammarström

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Two molecular assemblies with one Ru(II)-polypyridine photosensitizer covalently linked to one Ru(II)(bda)L2 catalyst (1) (bda = 2,2′-bipyridine-6,6′-dicarboxylate) and two photosensitizers covalently linked to one catalyst (2) have been prepared using a simple C-C bond as the linkage. In the presence of sodium persulfate as a sacrificial electron acceptor, both of them show high activity for catalytic water oxidation driven by visible light, with a turnover number up to 200 for 2. The linked photocatalysts show a lower initial yield for light driven oxygen evolution but a much better photostability compared to the three component system with separate sensitizer, catalyst and acceptor, leading to a much greater turnover number. Photocatalytic experiments and time-resolved spectroscopy were carried out to probe the mechanism of this catalysis. The linked catalyst in its Ru(II) state rapidly quenches the sensitizer, predominantly by energy transfer. However, a higher stability under photocatalytic condition is shown for the linked sensitizer compared to the three component system, which is attributed to kinetic stabilization by rapid photosensitizer regeneration. Strategies for employment of the sensitizer-catalyst molecules in more efficient photocatalytic systems are discussed.

Original languageEnglish
Pages (from-to)2742-2751
Number of pages10
JournalInorganic Chemistry
Volume54
Issue number6
DOIs
Publication statusPublished - Mar 16 2015

    Fingerprint

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Wang, L., Mirmohades, M., Brown, A., Duan, L., Li, F., Daniel, Q., Lomoth, R., Sun, L., & Hammarström, L. (2015). Sensitizer-catalyst assemblies for water oxidation. Inorganic Chemistry, 54(6), 2742-2751. https://doi.org/10.1021/ic502915r