BMag-2012 - University of Birmingham

22 The Birmingham Magazine
Money doesn’t grow on trees but an innovative
new method of manufacturing metal
carbides does.
Using leaf skeletons, Birmingham Fellow Zoe
Schnepp and colleagues at the Max Planck
Institute of Colloids and Interfaces in Potsdam,
have developed a simple process to create a
magnetic leaf. During the research, the team
converted the carbon of a leaf skeleton into
a complex iron carbide microstructure.
Metal carbides cover a wide range of
materials. Some of these are more familiar,
such as tungsten carbide, used in drill-bits,
while others are used as catalysts for
speeding up chemical reactions.
Iron carbides have been around for thousands
of years in steel manufacture, but it is difficult
to prepare pure iron carbide with a small
particle size. For many modern applications,
it’s the small particle size or high surface
area that is really important.
Metal carbides are particularly interesting at
the moment since they could replace expensive
and rare platinum as catalysts in many industrial
applications. One of the aims of Zoe’s work
is to develop iron carbide as a cheaper and
more sustainable alternative to platinum.
The magnetic leaf shows that it is possible
to fabricate iron carbide into really varied
and intricate structures.
To create the leaf, the team soaked a leaf
skeleton in iron acetate solution, which was
then dried in air and heated under nitrogen.
The leaf skeleton decomposed to a carbon-rich
matrix and the iron acetate decomposed to iron
oxide. Carbothermal reduction of the iron oxide
produces an iron carbide ‘leaf’.
Zoe said: ‘The most important and surprising
aspect was the leaf’s stability. We could pass
an electrical current through it and use that
energy to produce oxygen bubbles, without
the leaf being damaged.’
But where did the leaf skeleton idea come
from? Zoe explained: ‘I’m keen on crafts like
pottery, so I had some leaf skeletons! We
weren’t trying to make an artificial leaf from
a leaf skeleton – the idea is that you can take
GOING
GREEN
From an artificial leaf to growing vegetables and
improving air quality, the great outdoors is inspiring
research at Birmingham.
‘The idea is that you can
take any carbon-rich starting
material, such as fabric or
wood, and convert it into
a metal carbide replica.’
any carbon-rich starting material, such as
fabric or wood, and convert it into a metal
carbide replica.’
Since conducting this research, Zoe has
focused on producing metal carbides with
higher surface areas, using other materials
(high surface areas enable chemical reactions
to happen quickly. By making materials with tiny
pores, a very high surface area is produced in
a small amount of material).
She said: ‘We’ve produced an iron carbidebased
material that has really high activity as
a catalyst, which we’re excited about. I’m
planning to apply some of these materials
for artificial photosynthesis, using sunlight
to produce useful fuels, such as hydrogen.’
Zoe will be joining the University this autumn
as one of 55 Birmingham Fellows, outstanding
postdoctoral researchers appointed to
permanent academic posts with five years’
protected time for high-quality research.
The scheme is supported by the Circles of
Influence campaign. See the Vice-Chancellor’s
welcome on page 2 for further details.
Learn more
www.birmingham.ac.uk/staff/excellence/
fellows/about
www.birmingham.ac.uk/circlesofinfluence/