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Science 27 September 2002:
Vol. 297. no. 5590, pp. 2243 - 2245
DOI: 10.1126/science.1075035
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Reports

Efficient Photochemical Water Splitting by a Chemically Modified n-TiO2

Shahed U. M. Khan,* Mofareh Al-Shahry, William B. Ingler Jr.

Although n-type titanium dioxide (TiO2) is a promising substrate for photogeneration of hydrogen from water, most attempts at doping this material so that it absorbs light in the visible region of the solar spectrum have met with limited success. We synthesized a chemically modified n-type TiO2 by controlled combustion of Ti metal in a natural gas flame. This material, in which carbon substitutes for some of the lattice oxygen atoms, absorbs light at wavelengths below 535 nanometers and has a lower band-gap energy than rutile (2.32 versus 3.00 electron volts). At an applied potential of 0.3 volt, chemically modified n-type TiO2 performs water splitting with a total conversion efficiency of 11% and a maximum photoconversion efficiency of 8.35% when illuminated at 40 milliwatts per square centimeter. The latter value compares favorably with a maximum photoconversion efficiency of 1% for n-type TiO2 biased at 0.6 volt.

Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282, USA.
*   To whom correspondence should be addressed. E-mail: khan{at}duq.edu

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THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Optically directed molecular transport and 3D isoelectric positioning of amphoteric biomolecules.
D. G. Hafeman, J. B. Harkins IV, C. E. Witkowski II, N. S. Lewis, R. J. Warmack, G. M. Brown, and T. Thundat (2006)
PNAS 103, 6436-6441
   Abstract »    Full Text »    PDF »
Comment on "Efficient Photochemical Water Splitting by a Chemically Modified n-TiO2" (I).
A. Fujishima (2003)
Science 301, 1673a
   Full Text »    PDF »
Comment on "Efficient Photochemical Water Splitting by a Chemically Modified n-TiO2" (II).
C. Hagglund, M. Gratzel, and B. Kasemo (2003)
Science 301, 1673b
   Full Text »    PDF »
Comment on "Efficient Photochemical Water Splitting by a Chemically Modified n-TiO2" (III).
K. S. Lackner (2003)
Science 301, 1673c
   Full Text »    PDF »
Response to Comments on "Efficient Photochemical Water Splitting by a Chemically Modified n-TiO2".
S. U. M. Khan, M. Al-Shahry, and W. B. Ingler Jr. (2003)
Science 301, 1673d
   Full Text »    PDF »


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