Just add water: How scientists are using silicon to produce hydrogen on demand

January 22, 2013 by Charlotte Hsu, University at Buffalo
This is a close-up of spherical silicon nanoparticles about 10 nanometers in diameter. In Nano Letters, UB scientists report that these particles could form the basis of new technologies that generate hydrogen for portable power applications. Credit: Swihart Research Group, University at Buffalo

(Phys.org)—Super-small particles of silicon react with water to produce hydrogen almost instantaneously, according to University at Buffalo researchers.

In a series of experiments, the scientists created spherical about 10 in diameter. When combined with water, these particles reacted to form silicic acid (a nontoxic ) and —a potential source of energy for fuel cells.

The reaction didn't require any light, heat or electricity, and also created hydrogen about 150 times faster than similar reactions using silicon particles 100 nanometers wide, and 1,000 times faster than bulk silicon, according to the study.

The findings appeared online in on Jan. 14. The scientists were able to verify that the hydrogen they made was relatively pure by testing it successfully in a small fuel cell that powered a fan.

"When it comes to to produce hydrogen, nanosized silicon may be better than more obvious choices that people have studied for a while, such as aluminum," said researcher Mark T. Swihart, UB professor of chemical and and director of the university's Strategic Strength in Integrated Nanostructured Systems.

Credit: Swihart Research Group, University at Buffalo

"With further development, this technology could form the basis of a 'just add water' approach to generating hydrogen on demand," said researcher Paras Prasad, executive director of UB's Institute for Lasers, Photonics and (ILPB) and a SUNY Distinguished Professor in UB's Departments of Chemistry, Physics, Electrical Engineering and Medicine. "The most practical application would be for portable energy sources."

Swihart and Prasad led the study, which was completed by UB scientists, some of whom have affiliations with Nanjing University in China or Korea University in South Korea. Folarin Erogbogbo, a research assistant professor in UB's ILPB and a UB PhD graduate, was first author.

The speed at which the 10-nanometer particles reacted with water surprised the researchers. In under a minute, these particles yielded more hydrogen than the 100-nanometer particles yielded in about 45 minutes. The maximum reaction rate for the 10-nanometer particles was about 150 times as fast.

This transmission electron microscopy image shows spherical silicon nanoparticles about 10 nanometers in diameter. These particles, created in a UB lab, react with water to quickly produce hydrogen, according to new UB research. Additional images of the particles are available at http://www.buffalo.edu/news/releases/2013/01/017.html. Credit: Swihart Research Group, University at Buffalo

Swihart said the discrepancy is due to geometry. As they react, the larger particles form nonspherical structures whose surfaces react with water less readily and less uniformly than the surfaces of the smaller, spherical particles, he said.

Though it takes significant energy and resources to produce the super-small silicon balls, the could help power portable devices in situations where water is available and portability is more important than low cost. Military operations and camping trips are two examples of such scenarios.

"It was previously unknown that we could generate hydrogen this rapidly from silicon, one of Earth's most abundant elements," Erogbogbo said. "Safe storage of hydrogen has been a difficult problem even though hydrogen is an excellent candidate for alternative energy, and one of the practical applications of our work would be supplying hydrogen for fuel cell power. It could be military vehicles or other portable applications that are near water."

"Perhaps instead of taking a gasoline or diesel generator and fuel tanks or large battery packs with me to the campsite (civilian or military) where water is available, I take a hydrogen (much smaller and lighter than the generator) and some plastic cartridges of silicon nanopowder mixed with an activator," Swihart said, envisioning future applications. "Then I can power my satellite radio and telephone, GPS, laptop, lighting, etc. If I time things right, I might even be able to use excess heat generated from the reaction to warm up some and make tea."

Explore further: Research reveals nanotechnology simplifies hydrogen production for clean energy

More information: pubs.acs.org/doi/abs/10.1021/nl304680w

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1.2 / 5 (9) Jan 22, 2013
silicon-nine(nm) here we come, kin to Ice-nine
5 / 5 (1) Jan 22, 2013
They don't mention the implications of the thermal reaction. If hydrogen is created that quickly, would it be safe in something as small as a battery where heat can build up quickly?
3.3 / 5 (7) Jan 22, 2013
"The government, man? They've got this car... it runs on water, man! WATER!"

- Hyde
2.3 / 5 (3) Jan 22, 2013
Finely dispersed silicon [url=http://www.dbresearch.com/PROD/DBR_INTERNET_EN-PROD/PROD0000000000079095.pdf[/url] and it oxidizes rapidly at air. It creates a voluminous foam with water, which is difficult to separate from gas. Reaction with water is very exothermic - which means, a lotta energy introduced into production of silicon dust will be wasted as a heat during it.
3.7 / 5 (3) Jan 22, 2013
Finely dispersed silicon is pyrophoric and it oxidizes rapidly at air. It creates a voluminous foam with water, which is difficult to separate from gas. Reaction with water is very exothermic - which means, a lotta energy introduced into production of silicon dust will be wasted as a heat during it.
1.2 / 5 (13) Jan 22, 2013
This is exactly the useless research, which will become obsolete with cold fusion technology immediately. After all, whole the hydrogen economics is just a research jobs generating nonsense - if we need to replace the hydrogen with mixture of silicon and water to make it transportable, why we couldn't use the carbon hydrides, i.e. the synthetic gasoline made of coal and water for the same purpose? If nothing else, we could use the existing engines for it without change.
2.6 / 5 (14) Jan 22, 2013
"The Hydrogen Economy" seems to be the only part of the Bush presidency that the progressives have held dear to their hearts yet it has the least basis in reality.
5 / 5 (5) Jan 22, 2013
As always, the question is, "How much energy does it take to make the spheres, build the equipment to use it, and dispose of the waste?" Over the life of any energy system that makes use of this method, do we have positive or negative net energy and is it affordable, compared to conventional methods? Until these questions are answered, this is little more than a curiosity.
4.1 / 5 (9) Jan 22, 2013
MR166 - do you understand that this is a science web site - and that people from all across the world read the articles? It is not about your tiny political agenda - it is about science. Many of the articles are reporting on early research - some pan out - others don't - but again - it is not about politics.
5 / 5 (4) Jan 22, 2013
This is exactly the useless research, which will become obsolete with cold fusion technology immediately.

Yes, we should put all our eggs in one basket that might pay off in 30-40 years.
1 / 5 (5) Jan 22, 2013
we should put all our eggs in one basket that might pay off in 30-40 years
We shouldn't throw the most promising egg from the nest, because it could threat the weak hens in next 5 - 7 years (and save the human civilization before global nuclear war for the rest of oil sources). In addition, even without cold fusion it's recognizable quite easily, that the hydrogen technology is research jobs generator only, the silicon-mediated hydrogen technology the more. It's just impressively huge nonsense at so many levels for everybody, who can calculate the energetic effectiveness of the whole process.
1 / 5 (2) Jan 22, 2013
interesting result, but never likely to be practical for the reasons illustrated by commenters. Worthwhile reseach certainly, but no furthur funding should be allocated for such a niche fuel with such poor conversion efficiency.
not rated yet Jan 22, 2013
How much energy is required to produce the silicon metal that require to generate same amount of hydrogen that produce the energy needed?
not rated yet Jan 22, 2013
Would that be 1 or 2 test tubes of hydrogen per month ?
5 / 5 (2) Jan 23, 2013
Ug, I was practically yelling at the article to stop telling me it is faster than, just tell me how fast *it is*.
Simple Google look up right? A quick read gives me the impression that pure Si develops a protective layer of SiO2 and is then generally nonreactive to water. Although it is frequently the case that you up the surface area, you up a reaction rate (that is what "activated" charcoal is). So probably this kind of strategy means storing the Si powder away from oxygen.

Would also have been nice to see a comparison of energy density compared with batteries.

not rated yet Jan 23, 2013
I wonder what would happen if they milled silica oxide sand to about the right size particles, then remove the oxygen with pyrolysis. Would the silica plus trace minerals still work adequately without further purification?
5 / 5 (2) Jan 23, 2013
Just for clarity's sake: this isn't an energy source. It's more like a battery: you put energy in to create the silicon nanoparticles, then get energy out later on when it comes into contact with H2O.

I'm sure that more energy is consumed creating the nanoparticles than is harvested later by combining them with water. Which is why the scientists involved suggest using it only under select conditions, such as where grid power isn't available.

Even so, there's a lot of research and development ahead to deliver even that much from this research. Combining silicon nanoparticles and H2O generates waste heat and makes a bubbly mess. It'll take some clever designs to make it practical.
5 / 5 (1) Jan 23, 2013
At least this works at the laboratory level, which is more than can be said for CF.
5 / 5 (1) Jan 23, 2013
aHaaa! ... the 'activator' !!! Hard to believe that this work included a third ingredient: and this fact was not mentioned by anyone here.

That its identity was withheld triggers in me a certain hesitation to accept any thing the article reports!

Until the 'mystery ingredient' is identified the work can not be duplicated in any other lab .. the 'special knowledge' would not exist ..

How many 'con games' have started this way!?

I choose to withhold judgement and to retain my skepticism until full data is forthcoming ..

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