may hold the key to developing a viable hydrogen
economy, according to Jin
Zhang , professor of chemistry and biochemistry
at the University of California, Santa Cruz. Zhang
will receive $535,000 in grants from the U.S.
Department of Energy (DOE) for his part in two
research projects aimed at developing new technologies
for the production and storage of hydrogen fuel using
Producing hydrogen from water using solar energy is the focus of one of the
projects. Zhang is leading that effort and is also a coinvestigator on a second
project to develop a method for highly efficient hydrogen storage. Both of
the three-year projects rely on a novel approach to create nanostructured materials
with special properties. Nanostructure refers to dimensions on the scale of
billionths of a meter.
"The goal is to produce clean energy," Zhang said. "The idea of using solar energy
and water as a source of hydrogen is very attractive, and we believe nanostructured
materials can be used to do this efficiently."
The grants are among 70 hydrogen research projects funded through a $64 million
DOE initiative aimed at making vehicles powered by hydrogen fuel cells available,
practical, and affordable for American consumers by 2020. Zhang's collaborators
on the hydrogen production project are Yiping Zhao of the University of Georgia
at Athens and Wei Chen of Nomadics Inc. The hydrogen storage project is headed
by Zhao and also involves Matthew McCluskey of Washington State University.
Hydrogen offers an attractive alternative to fossil fuels because it is highly
efficient and clean. But major technological hurdles must be overcome to make
the use of hydrogen fuel practical.
The first hurdle is how to produce the hydrogen. Water molecules can be split
to form pure hydrogen and oxygen using electricity (a process called electrolysis).
But the environmental advantages of hydrogen would be lost if the electricity
used to generate it came from burning fossil fuels. Using solar energy to split
water and generate hydrogen is not a new concept, but Zhang says his team's
approach could lead to a device efficient enough for practical use.
"We want to build a device that you can put in the sun, fill it with water, and
get hydrogen without using any outside source of energy," Zhang said.
The device will integrate two kinds of solar cells--a photovoltaic cell to
produce electricity and a photoelectrochemical cell to produce hydrogen from
the electrolysis of water. Both will use specially designed materials based
on arrays of nanowires with uniform orientation. The main focus of the project
will be on developing these nanostructured materials to optimize the efficiency
of both the photovoltaic cell and the photoelectrochemical cell.
The researchers will use a technique called glancing angle deposition (GLAD)
to fabricate the nanowire arrays. Zhao is one of the pioneers in the development
of this technique for making nanowires and nanorods. Zhang's lab will focus
on characterizing the structure and properties of the materials Zhao makes
and evaluating their suitability for achieving the highest possible efficiencies
for the photovoltaic cell and the photoelectrochemical cell.
The hydrogen storage project will also involve using the GLAD technique to
fabricate nanostructured materials. One of the problems with hydrogen as a
fuel is that it is a bulky gas that is not easily transported and stored. A
promising solution is to store it in a solid form as a metal hydride compound.
Metal hydride nanostructures could greatly improve the efficiency of this type
of storage, Zhang said.
"Nanostructures have a much larger surface area than bulk materials, so they
could hold more hydrogen per unit weight," he said.
The researchers plan to find the optimum conditions for fabricating metal hydride
nanostructures to achieve highly efficient hydrogen storage.
"The key to our success in each of these projects is the material. We need to
understand the properties of these materials and then explore their applications
in devices," Zhang said.
Notes : ,You may contact Zhang at (831) 459-3776 or firstname.lastname@example.org.
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