Electron Transfer in Dye-Sensitised Semiconductors Modified with Molecular Cobalt Catalysts: Photoreduction of Aqueous Protons

Hdl Handle:
http://hdl.handle.net/10149/596690
Title:
Electron Transfer in Dye-Sensitised Semiconductors Modified with Molecular Cobalt Catalysts: Photoreduction of Aqueous Protons
Authors:
Lakadamyali, F. (Fezile); Reynal, A. (Anna); Kato, M. (Masaru); Durrant, J. R. (James); Reisner, E. (Erwin)
Affiliation:
Teesside University, School of Science & Engineering.
Citation:
Lakadamyali, F.; Reynal, A.; Kato, M.; Durrant, J. R.; Reisner, E. (2012) 'Electron Transfer in Dye‐Sensitised Semiconductors Modified with Molecular Cobalt Catalysts: Photoreduction of Aqueous Protons' Chemistry - A European Journal; 18 (48): 15464
Publisher:
Wiley-VCH Verlag
Journal:
Chemistry - A European Journal
Issue Date:
26-Nov-2012
URI:
http://hdl.handle.net/10149/596690
DOI:
10.1002/chem.201202149
Additional Links:
http://doi.wiley.com/10.1002/chem.201202149
Abstract:
A visible-light driven H2 evolution system comprising of a RuII dye (RuP) and CoIII proton reduction catalysts (CoP) immobilised on TiO2 nanoparticles and mesoporous films is presented. The heterogeneous system evolves H2 efficiently during visible-light irradiation in a pH-neutral aqueous solution at 25 °C in the presence of a hole scavenger. Photodegradation of the self-assembled system occurs at the ligand framework of CoP, which can be readily repaired by addition of fresh ligand, resulting in turnover numbers above 300 mol H2 (mol CoP)−1 and above 200,000 mol H2 (mol TiO2 nanoparticles)−1 in water. Our studies support that a molecular Co species, rather than metallic Co or a Co-oxide precipitate, is responsible for H2 formation on TiO2. Electron transfer in this system was studied by transient absorption spectroscopy and time-correlated single photon counting techniques. Essentially quantitative electron injection takes place from RuP into TiO2 in approximately 180 ps. Thereby, upon dye regeneration by the sacrificial electron donor, a long-lived TiO2 conduction band electron is formed with a half-lifetime of approximately 0.8 s. Electron transfer from the TiO2 conduction band to the CoP catalysts occurs quantitatively on a 10 μs timescale and is about a hundred times faster than charge-recombination with the oxidised RuP. This study provides a benchmark for future investigations in photocatalytic fuel generation with molecular catalysts integrated in semiconductors.
Type:
Article
Language:
en
ISSN:
09476539
Rights:
Publisher does not support open access. For full details see http://www.sherpa.ac.uk/romeo [Accessed 19/02/2016]

Full metadata record

DC FieldValue Language
dc.contributor.authorLakadamyali, F. (Fezile)en
dc.contributor.authorReynal, A. (Anna)en
dc.contributor.authorKato, M. (Masaru)en
dc.contributor.authorDurrant, J. R. (James)en
dc.contributor.authorReisner, E. (Erwin)en
dc.date.accessioned2016-02-19T11:10:22Zen
dc.date.available2016-02-19T11:10:22Zen
dc.date.issued2012-11-26en
dc.identifier.citationChemistry - A European Journal; 18 (48): 15464en
dc.identifier.issn09476539en
dc.identifier.doi10.1002/chem.201202149en
dc.identifier.urihttp://hdl.handle.net/10149/596690en
dc.description.abstractA visible-light driven H2 evolution system comprising of a RuII dye (RuP) and CoIII proton reduction catalysts (CoP) immobilised on TiO2 nanoparticles and mesoporous films is presented. The heterogeneous system evolves H2 efficiently during visible-light irradiation in a pH-neutral aqueous solution at 25 °C in the presence of a hole scavenger. Photodegradation of the self-assembled system occurs at the ligand framework of CoP, which can be readily repaired by addition of fresh ligand, resulting in turnover numbers above 300 mol H2 (mol CoP)−1 and above 200,000 mol H2 (mol TiO2 nanoparticles)−1 in water. Our studies support that a molecular Co species, rather than metallic Co or a Co-oxide precipitate, is responsible for H2 formation on TiO2. Electron transfer in this system was studied by transient absorption spectroscopy and time-correlated single photon counting techniques. Essentially quantitative electron injection takes place from RuP into TiO2 in approximately 180 ps. Thereby, upon dye regeneration by the sacrificial electron donor, a long-lived TiO2 conduction band electron is formed with a half-lifetime of approximately 0.8 s. Electron transfer from the TiO2 conduction band to the CoP catalysts occurs quantitatively on a 10 μs timescale and is about a hundred times faster than charge-recombination with the oxidised RuP. This study provides a benchmark for future investigations in photocatalytic fuel generation with molecular catalysts integrated in semiconductors.en
dc.language.isoenen
dc.publisherWiley-VCH Verlagen
dc.relation.urlhttp://doi.wiley.com/10.1002/chem.201202149en
dc.rightsPublisher does not support open access. For full details see http://www.sherpa.ac.uk/romeo [Accessed 19/02/2016]en
dc.titleElectron Transfer in Dye-Sensitised Semiconductors Modified with Molecular Cobalt Catalysts: Photoreduction of Aqueous Protonsen
dc.typeArticleen
dc.contributor.departmentTeesside University, School of Science & Engineering.en
dc.identifier.journalChemistry - A European Journalen
or.citation.harvardLakadamyali, F.; Reynal, A.; Kato, M.; Durrant, J. R.; Reisner, E. (2012) 'Electron Transfer in Dye‐Sensitised Semiconductors Modified with Molecular Cobalt Catalysts: Photoreduction of Aqueous Protons' Chemistry - A European Journal; 18 (48): 15464en
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