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Posted on 09/26/2007 8:32:50 AM PDT by Red Badger
Researchers at the Max Planck Institute for Bioinorganic Chemistry have developed a titanium disilicide (TiSi2) semiconductor photocatalyst that splits water into hydrogen and oxygen. The semiconductor also stores the gases produced, enabling the simple separation of hydrogen and oxygen.
Lead researcher Martin Demuth and his team report on their work in the current issue of Angewandte Chemie International Edition.
The generation of hydrogen and oxygen from water by means of semiconductors is an important contribution to the use of solar energy. Semiconductors suitable for use as photocatalysts have been difficult to obtain, have unfavorable light-absorption characteristics, or decompose during the reaction. —Martin Demuth
Demuth and his team proposed a class of semiconductors that have not been used for this purpose before: silicides. For a semiconductor, titanium disilicide has very unusual optoelectronic properties that are ideal for use in solar technology. In addition, this material absorbs light over a wide range of the solar spectrum, is easily obtained, and is inexpensive.
At the start of the reaction, a slight formation of oxide on the titanium disilicide results in the formation of the requisite catalytically active centers.
Another aspect of this system is the simultaneous reversible storage of hydrogen. The storage capacity of titanium disilicide is smaller than the usual storage materials, but it is technically simpler. Significantly lower temperatures are sufficient to release the stored hydrogen. The oxygen is stored as well, but is released under different conditions than the hydrogen, requiring temperatures of more than 100°C and darkness.
Demuth and his German, American, and Norwegian partners have founded a company in Lörrach, Germany, for the further development and marketing of the proprietary processes.
Resources:
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Peter Ritterskamp, Andriy Kuklya, Marc-André Wüstkamp, Klaus Kerpen, Claudia Weidenthaler, Martin Demuth. “A Titanium Disilicide Derived Semiconducting Catalyst for Water Splitting under Solar Radiation - Reversible Storage of Oxygen and Hydrogen”, Angew. Chem., Int. Ed., 2007 46 (41) 7770–7774 doi: 10.1002/anie.200701626
PING!.............
So each and every night you must wind the clock, put out the cat, and boil the hydrogen generator?
100°C is to release the OXYGEN. Substantially lower temp is for hydrogen..................
Wow!
Hey, sounds good to me! Release all that oxygen into the house and you wake up feeling like you just left an oxygen bar!
“100°C is to release the OXYGEN. Substantially lower temp is for hydrogen..................”
However, what is not clear is that if the system still functions with 100% capacity of oxygen. That is, must the oxygen be released in order for the catalyst to resume separation?
If it gets full of OXYGEN, you could have it attached to the HVAC of your house to automatically vent the oxygen back to the atmosphere using heat from the furnace, heating elements or AC compressor.............
At some point, I’m sure, the unit would “fill up” with oxygen, necessitating the venting of the trapped gas. But that would be a relatively simple procedure...............
Please Freep Mail me if you'd like on/off
Dilithium crystals have made this technology obsolete. I am still developing the warp drive for my Prius hybrid. So any developments in that department will be appreciated.
Before I jump on board I have to have the questions answered...and they are at the same website...but the first question is wrong.
(a) how expensive is it to manufacture a TiSi2 cell that can produce and store the gases and what is the value of the gas produced over the lifetime of the cell? (Production & Cost/benefit over time)
(b) what are its mechanical properties?
(c) what is the energy conversion efficiency for regular sunlight at perpendicular incidence?
(d) does the water film have to be between the semiconductor and a pane of glass, or can it be in the semiconductor’s shadow?
(e) is the heat fron strong sunlight sufficient for hydrogen desorption?
(f) how specific are the desorption processes?
I think they need to run a Level 3 Diagnostic before they put it into production.
All of that released oxygen will curb my hangover the next morning, too.
Thanks for the ping.
I think we are on the verge of a breakthrough in this area. I keep seeing things that suggest we will have cheaper & faster ways to split H2O, use the hydrogen, release the oxygen, and maybe even use salt water to do it so that there’s a possibility of desalinization as well. The areas that are most promising are nanotechnology, thin membrane osmosis, electrolysis assisted by solar or RF or some other energy, and well, this stuff.
Which will likely use more energy than the system will produce. So you still have a negative energy flow.
I have a couple spare flux capacitors...
An example:
Hydrogen-generating Technology Closer Than Ever
http://www.sciencedaily.com/releases/2007/08/070827174310.htm ^ | 8/27/07
http://www.freerepublic.com/focus/news/1887852/posts?page=87
Integrating all of these technologies could make for a great home appliance: A solar-powered Water Splitter and Heater. Water in, Hot Water + Hydrogen + Oxygen out.
And on the industrial scale, Salt Water in, H2O + NaCl out or also H2 + Oxygen + Heat to drive generators & hot water heaters & whatnot + NaCl out. Is salt good for anything?
Tequila shots!
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