Improved Photochemical Properties of Titania through the Ferroelectric Field Effect Gregory S. Rohre

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Improved Photochemical Properties of Titania
through the Ferroelectric Field EffectGregory S.
Rohrer, Carnegie Mellon University, DMR 0412886
Although TiO2 (titania) is a promising catalyst
for solar hydrogen production, its efficiency is
reduced by the recombination of charge carriers
before they react on the surface. We have
completed experiments to test the hypothesis that
a thin film of titania supported on a
ferroelectric substrate would have a higher
reactivity than the bulk material. It was found
that 10 nm thick (110) orientated rutile titania
had a much higher reactivity than much thicker
(bulk-like) films. This is because the
ferroelectric field effect separates both charge
carriers and oxidation and reduction sites on the
surface, making recombination less likely. This
principle might be used to make improved
catalytic materials. The atomic force microscope
images to the right show the titania thin film
surfaces (a) before and (b) after the
photochemical deposition of silver. The striped
pattern of silver indicates the influence of the
ferroelectric substrate.
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Educators use web site to exchange information on
teaching crystallography Gregory S. Rohrer,
Carnegie Mellon University, DMR 0412886
Use of the textbook, Structure and Bonding in
Crystalline Materials, has expanded since its
publication in 2001. The PI is in communication
with instructors at ten other universities using
this book. To enrich the experiences of both the
students and the instructors, a web site has been
created as a companion for those using the book.
The web site contains a compilation of errata,
the figures from the book, enrichment problems
not in the book, contemporary examples about
crystallography and bonding (intended to
communicate a recognition of the need for
lifelong scholarship and for knowledge of
contemporary issues in the application of
materials), and solved problems. The URL is
http//neon.materials.cmu.edu/rohrer/sbcm/sbcm.h
tml
Cover are from the text showing a SiC growth
surface