Download Posted on 05/04/2007 6:06:28 AM PDT by ovrtaxt
Cell splits water via sunlight to produce hydrogen
Cheap source of energy
By Tony Fitzpatrick
May 1, 2007 -- Engineers at Washington University in St. Louis have developed a unique photocatalytic cell that splits water to produce hydrogen and oxygen in water using sunlight and the power of a nanostructured catalyst. Pratim Biswas has developed a unique photocatlytic cell that splits water to produce hydrogen and oxygen using sunlight and the power of a nanostructured catalyst. The discovery provides a new, low cost and efficient option for hydrogen production and can be used for a variety of distributed energy applications.The group is developing novel methodologies for synthesis of nanostructured films with superior opto-electronic properties. One of the methods, which sandwiches three semiconductor films into a compact structure on the nanoscale range, is smaller, more efficient and more stable than present photocatalytic methods, which require multiple steps and can take from several hours to a day to complete.
The discovery provides a new, low-cost and efficient option for hydrogen production and can be used for a variety of distributed energy applications.
Pratim Biswas, Ph.D., the Stifel and Quinette Jens Professor and Chair of the Department of Energy, Environmental and Chemical Engineering, and his graduate student Elijah Thimsen, recently have developed the well-controlled, gas phase process, and have demonstrated it for synthesizing a variety of oxide semiconductors such as iron and titanium dioxide films in a single step process. It is based on a simple, inexpensive flame aerosol reactor (FLAR) and consists of four mass flow controllers to regulate process gases, a standard bubbler to deliver a precursor, a metal tube that acts as a burner and a water-cooled substrate holder.
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| David Kilper/WUSTL Photo |
| Pratim Biswas and his group have developed a method to make a variety of oxide semiconductors that, when put into water promote chemical reactions that split water into hydrogen and oxygen. The method provides a new low cost and efficient option for hydrogen production. |
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"We put these films in water and they promote some reactions that split water into hydrogen and oxygen," said Biswas. "We can use any oxide materials such as titanium dioxide, tungsten oxide and iron oxide in nanostructures sandwiched together that make very compact structures. The process is direct and takes only a few minutes to fabricate. More important, these processes can be scaled up to produce larger structures in a very cost effective manner in atmospheric pressure processes."
Collaborations have now been established with Dewey Holten, Ph.D., Washington University professor of chemistry in Arts & Sciences, to better understand the electron-hole pair kinetics, information that can then be used to tune the synthesis process. Other collaborations with Robert Blankenship, Ph.D., Washington University professor of biology and chemistry in Arts & Sciences, are being explored to create hybrid bio-nanostructures that will improve the light absorption efficiencies over a broader range of wavelengths. Electrospray and other aerosol techniques are being used to create these hybrid films.
The method was described in a recent issue of SPIE, a publication of the International Society for Optical Engineering.
Biswas will demonstrate the technique with a poster session May 6 at the International Symposium on Energy and Environment. |
Some of the department faculty — 14 members now, expected to double in five to ten years — are active in the University's ambitious BioEnergy Initiative, which is focused on the development of technologies for the production of next generation biofuels. The adoption of a systems approach will not only enable development processes for large volume production of liquid fuels from plant-based sources, but also at a low cost, and most importantly, in an environmentally benign manner — not only during the production, but also during the actual usage.
Wow, exciting news. We are on our way now.
Isn’t this a bad thing, according to the liberals won’t 02 affect the ozone?
Editor wanted; inquire within.
A small step here.... The question now is will it go anywhere. The answer? Who knows.
Cheap hydrogen would sure help in making fertilizer.
Ping!....
They'll have to sell this as getting rid of the biggest greenhouse gas of them all: Hydrogen hydroxide.
You’re hired!......You are Hired!........
The oil company hit squads have been mobilized...
The main thing that Islamic terrorists and Mr. Chavez are achieving is the economic and political incentives to make oil obsolete. The day is soon coming when we can tell these oil rich, jihadi jerks and their Socialist/Communist co-conspirators to “take a hike” and the world will become a much better place.
That was my thought. But the prof sez that these things can be built on a large scale and operated where sunlight is plentiful, like....the Middle East!!
It is my understanding that water is a finite thing, in other words, new water is not being created, just recycled.
When water evaporates, it does not break into hydrogen and oxygen, but remains bonded in the form of an H2O Molecule.
It then rises into the atmoshphere, where it bonds with other H2O molecules until it becomes heavy enough to fall back to Earth in the form of rain.
I am not a chemist, but from what I remember, and it may be wrong, this is why we don’t have a flooded Earth.
So if I am correct and water is not a renewable resource, what happens when we run out of water, and will “big water” companies suck up this technology and gouge us at the pumps like the oil companies are doing?
I’m sure that by the time this becomes practical, the liberals will find that water is our enemy.
I think I may have done that, editing the scripts out of the source code. doh!
If we can sell this tech to others (at hughly inflated rates) the better it is for us too!
That may be true; but when you burn hydrogen, all you're doing is recombining it with the oxygen you split it off of in the first place. The products of that reaction are thermal energy and H20, i.e. water. So no harm done.
Water vapor, a product of using hydrogen as a fuel, is the single largest contributor to the greenhouse effect.
Nah, you also need water.
Wouldn’t it be funny to sell them water at $75 a barrell?
No that is not quite correct, there are many process that create water, and vice-versa. A car engine made to run on Hydrogen produces water as its ‘exhaust’.
What you are thinking is that there is no ‘runaway’ process that would create a lot of water out of thin air (so to speak) that would lead to flooding. If that were possible a lot more planets would be wetter.
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