Two-electron photo-oxidation of betanin on titanium dioxide and potential for improved dye-sensitized solar energy conversion

The plant pigment betanin is investigated as a dye-sensitizer on TiO2 with regard to its potential to undergo two-electron oxidation following one-photon excitation. Electrochemical, spectroelectrochemical and transient absorption measurements provide evidence for two-electron proton-coupled photo-oxidation leading to a quinone methide intermediate which rearranges to 2-decarboxy-2,3-dehydrobetanin. Time-resolved spectroscopy measurements of betanin on nanocrystalline TiO2 and ZrO2 films were performed on femtosecond and nanosecond time-scales and provide evidence for transient species with absorption bands in the blue and the red. The results shed light on previous reports of high quantum efficiencies for electron injection and point the way to improved solar conversion efficiency of organic dye-sensitized solar cells.


Published in:
Proceedings of SPIE, 9165, 9165ON 1-9
Presented at:
Conference on Physical Chemistry of Interfaces and Nanomaterials XIII, San Diego, CA, AUG 17-20, 2014
Year:
2014
Publisher:
BELLINGHAM, WA, SPIE-INT SOC OPTICAL ENGINEERING
ISSN:
1996-756X
ISBN:
978-1-62841-192-8
Keywords:
Laboratories:




 Record created 2015-01-06, last modified 2018-10-01

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