Article originally published on dailymail in July
20th 2015.
Nanowire technology may
allow new types of hydrogen fuel cell for vehicles
- Scientists created a grid of tiny wires of gallium phosphide to split water
- This harnessed the sun's energy to generate hydrogen and oxygen
- They say this can be used to create a fuel cell that could power vehicles
- The new technology is 10 times more efficient than previous solar fuel cells
Solar-powered cars have come a step closer
after scientists discovered a way to create compact fuel cells that use the
power of the sun to generate hydrogen.
Researchers claim their method has
increased the efficiency of using solar cells to split water into its
constituent elements – hydrogen and oxygen – by a factor of ten.
They say the technique could finally allow
cars and other vehicles to be fitted with solar panels, overcoming problems
such as keeping the vehicles running at night.
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| Most attempts to build solar powered cars, like the one above, rely upon direct sunlight in order to provide the power needed to keep going, but new technology that has allowed scientists to use solar energy to split water into hydrogen and oxygen could provide compact solar fuel cells for powering vehicles even after dark. |
Rather than powering the
car directly, the solar panels could produce hydrogen and oxygen from water to
produce a fuel cell that can power the vehicles.
The scientists behind the technology say
this could provide a new clean replacement for traditional fossil fuels that
they have termed 'solar fuel'.
Professor Erik Bakkers, a nanoscientist at
Delft University of Technology in Delft, the Netherlands, who led the work,
said: 'Photoelectrochemical hydrogen production from solar energy and water
offers a clean and sustainable fuel option for the futureThey also say their
approach also uses ten thousands times less of the rare-metal semiconductor
used in modern solar panels, gallium phosphide.
'For the nanowires we needed ten thousand
less precious gallium phosphide material than in cells with a flat surface.
'That makes these kinds of cells
potentially a great deal cheaper.'
Creating hydrogen from solar energy has
been possible for some time, but it is extremely inefficient and expensive as
the amount of energy produced from solar panels is low.
Most solar cells uses silicon based
semiconductors to generate electricity from the sun, more recently gallium
phosphide has emerged as a new material.
Some approaches have connected a solar
cell to a battery, which stores up the energy until there is sufficient to
split the water into hydrogen and oxygen but this makes the technology heavy
and impractical for vehicles.
The researchers, whose work is published
in the journal Nature Communications, used a grid of tiny wires of gallium
phosphide measuring 500 nanometres long and 90 nanometres thick.
The gallium phosphide can convert sunlight
into electricity and split the water all in one, producing a solar fuel
cell.
Energy can be released from the fuel cell
by converting the hydrogen and oxygen back into water, releasing electricity.
This could lead to new compact
solar-powered fuel cells that can be used on vehicles.
They found this could be used to directly
split the water and could boost the yield of hydrogen by a factor of ten to
achieve a record for solar cell electrochemical hydrogen production by
converting 2.9 per cent of water into hydrogen.
However, the researchers say they have
still some way to go before they can reach the sort of yields that can be
obtained using batteries – which can convert 15 per cent of water into
hydrogen.
Solar powered vehicles usually rely upon
solar panels producing electricity to generate power for the vehicle, but these
either need large batteries to keep going after dark or cannot operate at
night.
Professor Bakkers said the new approach
they had developed could allow solar energy to be 'stored' as hydrogen and
oxygen for use even after dark.
He said: 'Gallium phosphide is also able
to extract oxygen from the water – so you then actually have a fuel cell in
which you can temporarily store your solar energy.
'In short, for a solar fuels future we
cannot ignore gallium phosphide any longer.
