Enhanced efficiency of the visible-light photocatalytic hydrogen generation by the ruthenium tris(2,2 '-bipyridyl)-methyl viologen system in the presence of cucurbit[n]urils

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Claudia G Gomes Silva (Author) FEUP; Maykel de Miguel (Author) Other; Belen Ferrer (Author) Other; Mercedes Alvaro (Author) Other; Hermenegildo Garcia (Author) Other

Journal

Title: Photochemical & Photobiological Sciences

Vol. 8

Pages: 1650-1654

ISSN: 1474-905X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 11 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-008-NPP

DOI: 10.1039/b9pp00063a

Abstract (EN): Cucurbiturils are cyclic oligomers of glycoluril units whose molecular shape defines an internal hollow space accessible through carbonyl portals. It is known that methyl viologen forms strong host-guest complexes with CB[7] and CB[8]. In the latter case even a dimer can be hosted inside CB[8]. Classical solution systems for visible light H(2) generation use methyl viologen as an electron relay. In this work we have found that the efficiency for H(2) generation of the photocatalytic system comprising EDTA-ruthenium tris(2,2'-bipyridyl)-methyl viologen-Pt increases when cucurbiturils are present in the solution. The enhancement follows the order CB[6] < CB[7] < CB[8]. By means of laser flash photolysis we have established that this efficiency increase arises from the combination of an increase in the relative quantum yield of charge separation (higher efficiency in the formation of MV(center dot+)) and a decrease of MV(center dot+) lifetime.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5