Betalain pigments for solar energy conversion in dye-sensitized TiO2 films

PHYS 508

Dongshe Zhang, dongshe88@yahoo.com1, Suzanne M. Lanier1, Jason L. Avent, Jaavent@mail.utexas.edu2, Jonathan A. Downing, jd1101@yahoo.com1, and Jeanne L. McHale, jmchale@wsu.edu1. (1) Department of Chemistry, Washington State University, PO Box 644630, Pullman, WA 99164-4630, (2) School of Biological Sciences, University of Texas at Austin, 1 University Station A6700, Austin, TX 78712-0183
Natural betalain dyes from beet roots and spinach berries are investigated for their potential for dye-sensitization of nanocrystalline TiO2. Preferential adsorption of yellow betaxanthin compounds on nanocrystalline TiO2 inhibits the adsorption of the red-purple betacyanins, but following column chromatography and acid treatment of the TiO2 film, good adsorption of purple betacyanins is observed. The red-purple betanin dye from beet roots (I) is found to give a solar energy conversion efficiency of about 0.7 %, while much lower efficiency is observed using gomphrenin (II). The basis for differences in solar energy conversion, stability and optical spectra of I and II will be considered.


Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006