2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009;
Pittsburgh, Pennsylvania
Session P38: Focus Session: Nanomaterials for Energy Applications I
8:00 AM–11:00 AM,
Wednesday, March 18, 2009
Room: 410
Sponsoring
Unit:
DCP
Chair: Nathaniel Rosi, University of Pittsburgh
Abstract ID: BAPS.2009.MAR.P38.1
Abstract: P38.00001 : Nanoscale Architectures for Energy Applications*
8:00 AM–8:36 AM
Preview Abstract
Abstract
Author:
Stanislaus Wong
(Department of Chemistry at the State University of New York at Stony Brook)
In my group, we have developed a number of different potential
architecture systems for gaining insights into energy storage
and photovoltaics. In one manifestation of our efforts,
generating a heterojunction comprising nanotubes and
nanocrystals, externally bound and connected, has been
significant. The unique, innovative, and important aspect
of this particular nanoscale architecture is that it takes
advantage of the tunability, in terms of size, shape, and
chemistry, of nanotubes and nanocrystals, to create a sharp
junction interface, whose properties are inherently
manipulable, tailorable, and hence, predictable. For example,
the electrical resistance of nanotube-nanoparticle networks is
dependent on the nanoscale junctions that exist between these
constituent nanomaterials as well as on microscale and
macroscale connectivity. Thus, rational design of these
nanomaterials is critical to a fundamental understanding of
charge transport in single molecules and the determination of
their conductance. Results on these systems can therefore be
used to increase understanding of intrinsic factors affecting
carrier mobility, such as electronic structure, carrier
trapping, and delocalization.
In a second manifestation, three-dimensional, dendritic micron-
scale spheres of alkali metal hydrogen titanate 1D
nanostructures (i.e.: nanowires and nanotubes) have been
generated using a modified hydrothermal technique in the
presence of hydrogen peroxide and an alkali metal hydroxide
solution. Sea-urchin-like assemblies of these 1D nanostructures
have been transformed into their hydrogen titanate analogues
by neutralization as well as into their corresponding
semiconducting, anatase titania nanostructured counterparts
through a moderate high-temperature annealing dehydration
process without destroying the 3D hierarchical structural
motif. The as-prepared hollow spheres of titanate and titania
1D nanostructures have overall diameters, ranging from 0.8 $\mu$m
to 1.2 $\mu$m, while the interior of these aggregates are vacuous
with a diameter range of 100 to 200 nm. We have demonstrated
that these assemblies are useful for example as active
photocatalysts for the degradation of synthetic Procion Red dye
under UV light illumination.
In a third set of experiments, a size- and shape-dependent
morphological transformation was demonstrated during the
hydrothermal soft chemical transformation, in neutral solution,
of titanate nanostructures into their anatase titania
counterparts. Our results indicate that as-synthesized
titania nanostructures possessed higher photocatalytic activity
than the commercial titania precursors from whence they were
derived.
*National Science Foundation and Department of Energy.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.P38.1