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Making Viruses Make Nanowires to Make Anodes
for Batteries
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by John Emsley
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Chemistry Top Ten
Papers
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Rank
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Papers
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Cites Jan-
Feb 08
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Rank
Nov-Dec 08
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1
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X. Huang, et al., "Cancer cell imaging and
photothermal therapy in the near-infrared region by using
gold nanorods," J. Am. Chem. Soc.,
128(6): 2115-20, 15 February 2006. [Georgia Inst. Tech.,
Atlanta; U. Calif., San Francisco] *014AX
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28
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†
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2
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Z.L. Wang, J. Song, "Piezoelectric nanogenerators
based on zinc oxide nanowire arrays,"
Science, 312(5771): 242-6, 14 April 2006. [Georgia
Inst. Tech., Atlanta; Peking U., Beijing, China] *032HK
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25
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†
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3
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K.T. Nam, et al., "Virus-enabled synthesis
and assembly of nanowires for lithium ion battery
electrodes," Science, 312(5775): 885-8,
12 May 2006. [MIT, Cambridge; Korea Inst. Sci. Tech.,
Seoul] *041JQ
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21
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†
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4
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I. McCulloch, et al., "Liquid-crystalline
semiconducting
polymers with high charge-carrier mobility,"
Nature Materials, 5(4): 328-33, April 2006. [Merck
Chem., Southampton, U.K.; Palo Alto Res. Ctr., CA; Stanford
U., CA; Stanford Synchrotron Radiat. Lab., Menlo Park, CA]
*029AO
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19
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†
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5
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M. Dinca, et al., "Hydrogen storage in a
microporous metal-organic framework with exposed
Mn2+ coordination sites," J. Am.
Chem. Soc., 128(51): 16876-83, 27 December 2007. [6
U.S. institutions] *118KQ
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19
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†
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6
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J. Song, Y. Wang, L. Deng, "The Mannich reaction of
malonates with simple imines catalyzed by bifunctional
cinchona alkaloids: Enantioselective synthesis of
ß-amino acids," J. Am. Chem. Soc.,
128(18): 6048-9, 10 May 2006. [Brandeis U., Waltham, MA]
*041PU
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18
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†
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7
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N.L. Rosi, et al.,
"Oligonucleotide-modified gold nanoparticles for
intracellular gene regulation," Science,
312(5776): 1027-30, 19 May 2006. [Northwestern U.,
Evanston, IL] *043UX
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18
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†
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8
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D. Enders, et al., "Control of four
stereocentres in a triple cascade organocatalytic
reaction," Nature, 441(7095): 861-3, 15
June 2006. [Aachen U., Germany] *052SL
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17
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7
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9
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J.E. Green, et al., "A 160-kilobit
molecular electronic memory patterned at 1011
bits per square centimetre," Nature,
445(7126): 414-7, 25 January 2007. [Caltech, Pasadena, CA;
U. Calif., Los Angeles; Ohio St. U., Columbus] *128WD
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17
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10
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A.G. Wong-Foy, A.J. Matzger, O.M. Yaghi,
"Exceptional H2 saturation uptake in microporous
metal-organic frameworks," J. Am. Chem.
Soc., 128(11): 3494-5, 22 March 2006. [U. Michigan,
Ann Arbor] *025XD
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16
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8
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SOURCE: Thomson Scientific's
Hot Papers Database. Read the
Legend.
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Four of the current Hot Ten papers relate to nano chemistry: #1 and #7 are
about gold nanorods and #2 is about zinc oxide nanowires. However, it is
paper #3 which is the most innovative, reporting how cobalt oxide
(Co3O4) nanowires have been assembled with the help
of a virus.
The paper comes from a team headed by Angela Belcher of the Department of
Materials Science and Engineering at MIT. It also describes how these
nanowires can form a monolayer which can act as the anode for an ultra-thin
lithium ion battery. Not surprisingly, Belcher’s work has attracted a
lot of media attention. In 2004 she was rewarded with a prestigious
MacArthur Fellowship and in 2006 was named by Scientific American
magazine as its Research Leader of the Year.
Employing a virus to carry out an inorganic chemical process
requires a quantum jump of scientific intuition, although some living
species have evolved to do just that. For example, sea snails can
manipulate calcium carbonate to construct their protective shells. In fact
it was these tiny creatures which Belcher says gave her the idea that
microscopic life forms might be able to construct other inorganic
materials.
She was proved right when her group used the M13 virus, which has 2,700
helical proteins wrapped around its DNA, to grow crystalline nanowires of
Co3O4. The virus was modified by attaching
tetraglutamate groupings to it, and these acted as templates for the
nanowires which grew within 30 minutes from a dilute (1 mM) aqueous cobalt
chloride solution at room temperature. They were then reduced with sodium
borohydride followed by spontaneous oxidation in water to yield the desired
product. Their authenticity as nanowires was proved using transmission
electron microscopy which revealed their genuinely crystalline nature.
The anodes for the lithium battery were made by mixing the nanowires with
15% of carbon black and 11% of poly(vinylidene
fluoride)-hexafluoropropylene binder. (The electrolyte was lithium
hexafluorophosphate in ethylene carbonate and dimethyl carbonate.) The
capacity of the new batteries was twice that of the normal carbon-based
anode batteries. Belcher was also able to show that the virus itself was
stable within the battery anode and there was no decomposition when the
battery went through a sequence of charging and discharging. The inclusion
of gold in the process led to hybrid Au-Co3O4
nanowires, and these increased the storage capacity compared to
Co3O4 nanowires alone.
Paper #3 also reports that M13 viruses can form very ordered
two-dimensional liquid crystalline layers of nanowires on top of conducting
films and that these can be as large as 10 cm2 in area. The
thickness of the multilayered polymer can be varied from 10 nm to several
micrometers and is independent of the substrate.
Talking to Science Watch®, Belcher
says her current research is being conducted with MIT colleagues Paula
Hammond and Yet-Ming Chiang: "We have been working on high specific
capacity cathode materials using biological processing and getting very
good results. We now have full virus-based battery cathodes as well
as anodes. We are also working on materials for solar cells, catalysts,
fuel cells and carbon sequestration."
Belcher’s collaborative work on multilayers assembled with the aid of
viruses has recently been published—see P.J. Yoo, et al.,
ACS Nano, 2(3): 561-71, 2008; and P.J. Yoo, et
al., Nano Letters, 8(4): 1081-9; 2008.
And what does she see in the future?
Belcher: "I think in the next few years new kinds of interdisciplinary
approaches to the synthesis and assembly of high-value, high-performance
materials will be much more acceptable. I also think that environmentally
friendly processing and environmental compatibility will become
increasingly important."
Belcher has opened up a completely new era of chemical synthesis by using
viruses to create and design inorganic nano-sized materials. One day we may
all benefit from her batteries which are not only efficient but transparent
and capable of powering all kinds of nano devices. And just as living
things with inorganic components are able to repair these themselves, so
might this ability even become a feature of nano components.
Dr. John Emsley is based at the Department of Chemistry, Cambridge
University, U.K.
Keywords: Angela Belcher, MIT, cobalt oxide nanowires, nanowires, M13
virus, lithium batteries, nanotechnology.
What's Hot In... : What's Hot In Chemistry Menu : Materials Scientists Harness Viruses for Battery Power
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