Graphene: it's Applications and Uses
The properties of graphene, carbon
sheets that are only one atom thick, have caused researchers and companies to
consider using this material in several fields. The following survey of
research activity introduces you to many potential applications of
A Survey of Applications:
Glucose measurement. Researchers at the University of Bath are developing
a graphene based sensor to
measure glucose levels without requiring a finger prick blood test.
Hydrogen production without platimum. Researchers
have demonstrated a catalyst made from
graphene doped with cobalt
can be used to produce hydrogen from water. The researchers at looking
at this method as a low cost replacement for platimum based catalysts.
Lower cost of display screens in mobile
devices. Researchers have found that graphene can replace indium-based
electrodes in organic light emitting diodes (OLED). These diodes are used in electronic
device display screens which require low power consumption. The use of graphene instead of indium not only reduces the
cost but eliminates the use of metals in the OLED, which may make
devices easier to recycle.
Lithium-ion batteries that recharge faster. These
batteries use graphene on the surface of the anode surface. Defects in
the graphene sheet (introduced using a heat treatment) provide pathways
for the lithium ions to attach to the anode substate. Studies have shown
that the time needed to recharge a battery using the
graphene anode is much
shorter than with conventional lithium-ion batteries.
Ultracapacitors with better performance than batteries.
These ultracapacitiors store electrons on graphene sheets, taking
advantage of the large surface of graphene to provide increase the
electrical power that can be stored in the capacitor. Researchers are
projecting that these
will have as much electrical storage capacity as lithium ion batteries
but will be able to be recharged in minutes instead of hours.
Components with higher strength to weight ratios. Researchers have found that adding graphene to epoxy
composites may result in stronger/stiffer components than epoxy
composites using a similar weight of carbon nanotubes. Graphene appears
to bond better to the
polymers in the epoxy, allowing a more effective coupling of the graphene into the structure of the composite. This
property could result in the manufacture of components with high
strength to weight ratio for such uses as windmill blades or
Storing hydrogen for fuel cell powered cars.
graphene layers to increase the binding energy of hydrogen to the
graphene surface in a fuel tank, resulting in a higher amount of
hydrogen storage and therefore a lighter weight fuel tank. This could
help in the development of practical hydrogen fueled cars.
Lower cost fuel cells. Researchers at Ulsan National Institute of Science and Technology
have demonstrated how to produce
edge-halogenated graphene nanoplatelets
that have good catalytic properties. The researchers prepared
the nanoplatelets by ball-milling graphene flakes in the presence of
chlorine, bromine or iodine. They believe these halogenated
nanoplatelets could be used as a replacement for expensive platinum
catalystic material in fuel cells.
Low cost water desalination: Researchers have
determined that graphene with
holes the size of a nanometer or less can be used to remove ions
from water. They believe this can be used to desalinate sea water at a
lower cost than the reverse osmosis techniques currently in use.
Lightweight natural gas tanks: Researchers at Rice
University have developed a composite material using plastic and
graphene nanoribbons that
block the passage of gas molecules. This material may be used in
applications ranging from soft drink bottles to lightweight natural gas
More efficient dye sensitized solar cells. Researchers at Michigan Technological University
have developed a honeycomb like
structure of graphene in which the graphene sheets are held apart by
lithium carbonate. They have used this "3D graphene" to replace the
platinum in a dye sensitized solar cell and achieved 7.8 percent
conversion of sunlight to electricity.
Electrodes with very high surface area and very low electrical resistance.
Researchers at Rice University have developed electrodes made from
nanotubes grown on
graphene. The researchers first grow graphene on a metal substrate
then grow carbon nanotubes on the graphene sheet. Because the base of
each nanotube is bonded, atom to atom, to the graphene sheet the
nanotube-graphene structure is essentially one molecule with a huge
Lower cost solar cells: Researchers have built a
solar cell that uses graphene as a electrode while using buckyballs and
carbon nanotubes to absorb light and generate electrons;
making a solar
cell composed only of carbon. The intention is to eliminate the need
for higher cost materials, and complicated manufacturing techniques
needed for conventional solar cells.
Transistors that operate at higher frequency. The ability to build
transistors with graphene is possible because of the higher speed at
which electrons in graphene move compared to electrons in silicon. Researchers are also developing
techniques that can be used to fabricate integrated circuits based
Sensors to diagnose diseases. These sensors are based upon graphene's
large surface area and the fact that molecules that are sensitive to
particular diseases can attach to the carbon atoms in graphene. For example,
researchers have found that graphene, strands of DNA, and fluorescent molecules
can be combined to diagnose diseases. A sensor is formed by attaching fluorescent molecules to single strand DNA and then
attaching the DNA to graphene. When an identical single strand DNA
combines with the strand on the graphene a double strand DNA if formed
that floats off from the graphene, increasing the fluorescence level.
This method results in a
sensor that can detect the same DNA
for a particular disease in a sample.
Membranes for more efficient separation of gases.
These membranes are made from sheets of
graphene in which
nanoscale pores have been created. Because graphene is only one atom
thick researchers believe that gas separation will require less energy
than thicker membranes.
Chemical sensors effective at detecting explosives.
sensors contain sheets of
graphene in the form of a foam which changes resistance when low
levels of vapors from chemicals, such as ammonia, is present.