Exploring effects of intermittent light upon visible light promoted water oxidations

Dominic Walsh, Pascaline Patureau, Karen Robertson, Shaun Reeksting, Anneke Lubben, Salvador Eslava, Mark Weller

Research output: Contribution to journalArticle

Abstract

Visible light promoted photocatalytic water oxidations for potential solar fuel production have been studied widely, with many reports on optimization of reagent components. Here we report an exploration on the effects upon ongoing reactions of daylight equivalent light intensity illumination with regulated short dark periods of a few seconds duration as compared to standard continuous illumination. Comparison was made with systems employing synthesized low cost earth abundant iron oxide, calciumoxomanganite and cobalt oxide nanoparticulate catalysts together with a [Ru(bpy)3]2+ light harvesting dye and an electron acceptor. Yields of gaseous O2 and proton production were measured in situ and in real time. The study found that low cost catalysts could give very significantly increased O2 yields, turn over frequency and improved reaction profiles by use of simple on/off illumination. A range of timings with identical overall photon flux were tested and an optimum determined. Analysis of effects upon the light sensitizer under the range of lighting conditions (through mass spectrometry and UV-vis measurements), together with implementation of a continuous flow system as comparison to the batch reactions, were all employed to help elucidate the mechanisms for the clear improvements in reaction yields observed. These are believed to stem from reduction in self-decomposition of excess oxidized sensitizer and better synchronization of cyclic sensitizer oxidation/reductions with water oxidation at the metal oxide surface at specific light on : off timing
LanguageEnglish
Pages2101-2109
Number of pages9
JournalSustainable Energy & Fuels
Volume1
Issue number10
Early online date26 Sep 2017
DOIs
StatusPublished - 1 Dec 2017

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Oxidation
Lighting
Water
Catalysts
Oxides
Mass spectrometry
Protons
Costs
Synchronization
Coloring Agents
Photons
Metals
Earth (planet)
Fluxes
Decomposition
Electrons

Cite this

Exploring effects of intermittent light upon visible light promoted water oxidations. / Walsh, Dominic; Patureau, Pascaline; Robertson, Karen; Reeksting, Shaun; Lubben, Anneke; Eslava, Salvador; Weller, Mark.

In: Sustainable Energy & Fuels, Vol. 1, No. 10, 01.12.2017, p. 2101-2109.

Research output: Contribution to journalArticle

Walsh, Dominic ; Patureau, Pascaline ; Robertson, Karen ; Reeksting, Shaun ; Lubben, Anneke ; Eslava, Salvador ; Weller, Mark. / Exploring effects of intermittent light upon visible light promoted water oxidations. In: Sustainable Energy & Fuels. 2017 ; Vol. 1, No. 10. pp. 2101-2109.
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