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Power Science

Alloy Could Produce Hydrogen Fuel Using Sunlight 360

intellitech writes "Using state-of-the-art theoretical computations, a University of Kentucky-University of Louisville team demonstrated that an alloy formed by a 2 percent substitution of antimony (Sb) in gallium nitride (GaN) has the right electrical properties to enable solar light energy to split water molecules into hydrogen and oxygen, a process known as photoelectrochemical (PEC) water splitting. When the alloy is immersed in water and exposed to sunlight, the chemical bond between the hydrogen and oxygen molecules in water is broken (abstract). Because pure hydrogen gas is not found in free abundance on Earth, it must be manufactured by unlocking it from other compounds. Thus, hydrogen is not considered an energy source, but rather an 'energy carrier.' Currently, it takes a large amount of electricity to generate hydrogen by water splitting. As a consequence, most of the hydrogen manufactured today is derived from non-renewable sources such as coal and natural gas. The team says the GaN-Sb alloy has the potential to convert solar energy into an economical, carbon-free source for hydrogen."
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Alloy Could Produce Hydrogen Fuel Using Sunlight

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  • by jcr ( 53032 ) <> on Wednesday August 31, 2011 @12:23AM (#37261572) Journal

    Is this a superior alternative to the work that Dan Nocera's been doing at MIT with catalysts to make electrolysis take less energy?


    • Re: (Score:3, Interesting)

      by Squiddie ( 1942230 )
      Maybe they can combine it? I don't know, I'm not a chemist and I haven't read the abstract, but it would be interesting.
    • by currently_awake ( 1248758 ) on Wednesday August 31, 2011 @12:43AM (#37261702)
      Having solar panels on your roof that can power your stuff -and- refuel your car is a better investment than a solar plant for each.
      • by mcrbids ( 148650 ) on Wednesday August 31, 2011 @01:46AM (#37261922) Journal

        Why, particularly? I would guess that which one would be "better" would be a calculation that combines ease of access, cost, aesthetics, and ROI. Often, operations done at large scale can be done more efficiently than in a distributed fashion. Other times, the cost of distribution can offset this interent efficiency.

        We don't yet know which one is "better" - the market is still merging.

        One area that I'd personally love to see more solar panels is over parking lots. Nothing quite beats the misery of walking out of a nice, 75 degree mall into the blistering, 100-degree heat in the summer time, only to sit down in your 160 degree car, cursing and swearing at all that damned free energy the sun packed into your car.

        But cover that parking lot with a lattice of solar panels so I'm getting into a merely hot 95 degree car while all that energy is used to power the A/C at the mall I just got out of, that would be swell.

        • Re: (Score:3, Insightful)

          by Stormwatch ( 703920 )

          Nothing quite beats the misery of walking out of a nice, 23 degree mall into the blistering, 37 degree heat in the summer time, only to sit down in your 71 degree car, cursing and swearing at all that damned free energy the sun packed into your car.

          Fixed that for you. Now stop using those damn Fred Flintstone units!

          • LOL, we need a metrification plugin for Firefox so that we don't have to hear the rest of the world complain about how we measure our milk :)

          • by Anonymous Coward on Wednesday August 31, 2011 @08:02AM (#37263170)

            Nothing quite beats the misery of walking out of a nice, 296 Kelvin mall into the blistering, 310 Kelvin heat in the summer time, only to sit down in your 344 Kelvin car, cursing and swearing at all that damned free energy the sun packed into your car.

            Fixed that for you. It's 21st century already.

    • I'm too lazy to install VPN software to get article access from my couch, but the abstract only discusses the 2.0 eV absorption, which is about 620 nm. That is certainly one of the wavelengths of interest, being near the solar spectrum max irradiance, but if the catalyst doesn't absorb at any other wavelengths, it'll not be of much use at all. The other thing to consider, of course, is that Nocera's catalysts are already made and just being industrialized, while the controlled doping of this particular Sb

      • Standard PV cells are single band gap. You can get over 20% efficiency with a single band-gap, with a optimal band gap I think you can get to almost 30% IIRC. Higher than that needs more bandgaps/junctions.

        At 20% these would be very useful if they are cheap.
      • TFA says this is a theoretical result, and they're currently trying to make the actual alloy to see if it's practical.

      • by chihowa ( 366380 ) *

        I'm too lazy to install VPN software to get article access from my couch

        Most schools have an EZproxy or similar system available through the library. A quick bookmarklet in the style of [javascript:void((function()%7Blocation.href=location.href.replace(/%5Ehttp%5C:%5C/%5C/(%5B%5E%5C/%5C@%5D+)%5C/(?:)/,%22http://0-%22+%22$1%22.replace(%22%5C:%22,%22.%22);%7D)())] can allow easy journal access without having to screw with VPNs and such.

  • by Ironchew ( 1069966 ) on Wednesday August 31, 2011 @12:26AM (#37261586)

    Is there a cheap way to contain hydrogen yet?

    • No, hydrogen is still a bad investment.
      • by TWX ( 665546 )

        Heh. There's an entirely different truth in this statement.

        If this truly works, and the ability to produce hydrogen is, cost-wise, limited to the initial purchase cost of the equipment, the roof space, and the water bill, I wouldn't be surprised if some very, very powerful and rich companies that are currently making the bulk of their money by pulling hydrocarbons out of the ground work as hard as they can to purchase and/or stomp in to the ground a technology potentially this revolutionary.

        Remember, fossi

        • It's likely I have the roof space on my house to generate all of the hydrogen I'd need for all of my vehicles.

          I'll just pick on this one point. This is in fact very unlikely, and very very unlucky for a large majority of people.

          You claim the oil companies will kill this but you totally misunderstand them. They will be more than happy to refine hydrogen on a massive scale and bring it to stations just like today for the many, many people who cannot or will not put all this equipment together. They don't

          • by EdIII ( 1114411 )

            Problem is that you cannot safely transport hydrogen in a car. Sure... if you want to be in a bomb go ahead.

            That's why there has been so much research into metal hydride storage. Storing compressed hydrogen is insanity, IMO.

            I know there has been some very promising developments in point source hydrogen production using Aluminum and Gallium, but then the true costs are recycling the Aluminum back. Basically it would work out quite well, but we would need to build 50 nuclear plants in the US to provide the

            • ... At least, not compared to petrol. The major point is that, should the tank rupture, the light hydrogen safely escapes upwards. Even explosions tend to safely float up.

        • very powerful and rich companies that are currently making the bulk of their money by pulling hydrocarbons out of the ground work as hard as they can to purchase and/or stomp in to the ground a technology potentially this revolutionary.

          Yeah, they'd much rather be in the filthy, risky oil-business with all it's lawsuits and political-backstabbings. All this clean, carbon-neutral fancy, schmancy high tech stuff has to be stamped out no matter what.

          PS: Much more likely they'll try to monopolize it.

    • Who cares, 'burn' it right there and use the energy to pump water uphill.

      If it works, which I doubt.

      • by Surt ( 22457 )

        Energy stored as the potential energy against gravity of large volumes of water is not the most convenient of automotive fuels.

        • by Calos ( 2281322 )

          You're right, but for the wrong reasons. I could substitute "gasoline" for "water" in what you said and it would sound equally plausible.

          If I'm understanding you correctly. I'm not sure I am, I'm still parsing and reparsing what you said.

          Regardless, to the GP: don't use the power generated by combusting the hydrogen to pump the water uphill. Let electrolysis form gas which will naturally want to rise to the top of the hill, and burn it there to turn it back into water.

          • The energy released by burning hydrogen is sufficient to raise the resulting water to an altitude of more than 1600KM. Or, burning two grams of hydrogen is enough to raise 3 liters of water to the top of Mt. Everest.
      • by jamesh ( 87723 )

        Who cares, 'burn' it right there and use the energy to pump water uphill.

        If it works, which I doubt.

        My car won't run on uphill water.

    • Just make your hydrogen to use in the chemical plants this way instead of reforming natural gas. Ammonia, ammonium sulphide etc etc comes from hydrocarbons now and it's nice to have an alternative way of getting it for when oil and natural gas get to be rare and expensive things.
    • by Plammox ( 717738 )
      These guys are working on a solution: Solid H-storage [].
    • If all else fails you could stick some carbon onto it. Then you've got something we know how to deal with.
    • by whit3 ( 318913 )

      Three ways.
      Compressed gas (not really safe, compressed H2
      causes embrittlement of metals eventually).

      Liquefied gas (safe enough unless you want a mobile
      tank, like in an automobile) - can vent large amounts
      of material rapidly if the tank is breached

      Intercalation. Hydrogen can weakly bond to some
      kinds of surfaces (like O2 bonds to hemoglobin),
      and this allows storage at low pressure of lots of
      room-temperature H2. It's only capable of outgassing
      slowly, because release of H2 cools the intercal

  • by cryfreedomlove ( 929828 ) on Wednesday August 31, 2011 @12:27AM (#37261598)
    Do you care about your fellow man who was born with less privilege than you? Then work hard to make stories like this into a reality so that every poor family can have the access to cheap energy to heat their homes and to power the car in their driveway.

    That's a better story than lowering the standard of living for everyone. I'd rather use technology to raise everyone up, even if it is only to the modest levels that you and I take for granted.
    • Access to energy is social justice

      So, it's unjust that I pay for the energy I use now, and pay taxes to subsidize some of what it takes to develope, transport, and secure it?

      What you're saying is that I'm not being treated fairly because I have to pay? Or are you saying that people who don't pay for the energy they use are being treated unjustly? Or is it the people who don't pay for the energy they don't use? This whole justice thing is confusing. Here, let me look that up...

      Hmmm. No. I couldn't find a definition of "justice" that m

      • Re: (Score:2, Insightful)

        by hedwards ( 940851 )

        Wow, let me bask in the glow of your self entitlement.

        Social justice means recognizing that all men were not born with equal opportunity. It's a notion which conservatives tend to ignore, but the reality is that a person growing up poor, black and let's say blind is not going to have the same road to prosperity that somebody that's born black and sighted or black, sighted and rich wil.

        Social justice recognizes that anybody can fall on hard times, no matter how careful they are, and that there's dignity in a

        • Wow, let me bask in the glow of your self entitlement

          No, what you're saying is that I'm not entitled to things I do myself, but other people are entitled to what I do.

          Just because you're lucky enough not to have to worry about such things does not mean that you have any more right to them than anybody else does

          Who says I don't worry about suddenly becoming blind, or poor, or injured and unable to work? Other than you, I mean, since you know.

          I've seen the folks that work janitorial and in kitchens and chances are good that they work harder than you do for less.

          Really? I work about 90 hours a week, and haven't had a single week actually "off" in about ten years. Nobody paid my way through college - I didn't get to go, because I had to work. Hey, look! Horrible injustice - somebody else got something I didn't get! I bet

          • by indeterminator ( 1829904 ) on Wednesday August 31, 2011 @03:41AM (#37262336)

            Really? I work about 90 hours a week, and haven't had a single week actually "off" in about ten years.

            Selfish bastard. You could share some of that work, there's enough to do for two or three people there.

        • by jcr ( 53032 ) <> on Wednesday August 31, 2011 @02:01AM (#37261996) Journal

          Social justice means recognizing that all men were not born with equal opportunity.

          Nope, "social justice" is a propaganda term used to rationalize looting. Justice, or the lack thereof, only pertains to an individual, not to whatever categories you seek to divide people into.


          • "To rationalize looting"? You seriously think that? Lemme guess, you also think that taxes are slavery, right?

            Man, the entitlement sense some people have! You don't even realize how many benefits you get from having a stable society, do you?

    • Yea, you got it, but look - if I have to pay another $0.1 per litre for this to work, then get lost. I like my standing in the world, and I don't want everybody else to enjoy anything even close to it.

      So stick your solar utopian dream into your next bowl and puff away. If we wanted to help the world, why would we behave like we do?

      Big Oily Brother protects our superiority.

      • I think most of us would be willing to pay an extra $0.1 per litre, or even significantly more than that, if it meant lifting the world out of poverty. A lot of us do pay money to help people out. But it's hard to trust that the money would go to fund another war, or oil company tax-breaks, or another bailout. If that's the case, might as well keep the money in my own wallet, you know?
    • In the free market, the customer-base with the most money usually rule. Technological developments are usually targeted and priced for the wealthy, simply because there aren't much money in poor people.

      Only after saturating the upper- and middle-class markets, there might be leftover-scrapes for the lower-class, either by lowering the price closer to manufacturing costs, or simply through resale of used devices. At that point though, the upper- and middle-classes are on the next cool thing, while the lower-

      • There is plenty of money in the poor. Why do you think that the Walton family occupies something like half the top 10 slots in the Forbes list?
    • by MarkvW ( 1037596 )

      It seems to me that energy is too important to be left to private enterprise. Let the people control the energy.

      Billing (read: taxation) based upon energy usage would be about the fairest tax imaginable.

  • "But will never be made commercially available because it would result in a breakdown of the energy cartel's strangle-hold on the world's economy."
    • "Conspiracy theories appeal to those who are more familiar with how Hollywood works than with the real world." Amazing what quotation marks can do.
  • Imagine you're stuck in the desert with a bottle of water... you have to take a pick whether you drink your water or pour it in your car

    • Imagine you're stuck in the desert with a bottle of water... you have to take a pick whether you drink your water or pour it in your car

      Is that a real question? Of course you pick the car. It provides mobile shade in which to search for more water.

      • Or, you could take the door off the car, keep the water and go searching for more water on foot. And if it get hot, just roll the window down on the car door you are carrying.

    • by Anonymous Coward on Wednesday August 31, 2011 @12:45AM (#37261714)

      Imagine you're stuck in the desert with a bottle of water... you have to take a pick whether you drink your water or pour it in your car

      Easy answer really. Drink your water and pee on your car.

  • "Novel Alloy Could Produce Hydrogen Fuel from Sunlight"
    "University of Louisville and University of Kentucky researchers are currently working toward producing the alloy and testing its ability to convert solar energy to hydrogen"
    "The researchers say their findings are a triumph for computational sciences, one that could potentially have profound implications for the future of solar energy."
    "The GaN-Sb alloy is the first simple, easy-to-produce material to be considered a candidate for PEC water splitting."

    • by snl2587 ( 1177409 ) on Wednesday August 31, 2011 @01:01AM (#37261770)

      ChE here. I read the article (hooray for university journal access), and I know exactly why there's so much hedging: this is a purely computational, DFT paper, with no experimental results to back it up. In the academic world this is not particularly uncommon, and DFT studies are an amazingly powerful tool to identify (potentially) optimal material combinations that would take researchers centuries to discover by systematic experimentation. But that's just it: "potentially". DFT often (necessarily) overlooks potential external effects that only occur in real systems. Somebody higher up really jumped the gun by making a full press release on a typical journal article in the photocatalysis field.

      • Also, I know of many photocatalysts that conduct water splitting, though many require a light sensitizer (way too complex to explain when I'm this tired) or a separate semiconductor with an appropriate band gap. The only thing that's potentially exciting for the photocatalysis guys I know is that the doped semiconductor could serve as a complete system that could beat other complete systems (like titania)...but only experimentation will say for sure.
        • Of course the efficiency of the photocatalyst in using electromagnetic radiation to perform electrolysis is only 1/2 of the problem.

          The other problem is how to prevent corrosion of the catalytic surface that allows the catalyst to work long enough so that it can be used in a practical system. The DOE is basically funding research in this area and their goal for a practical material is 10,000 hours (a little over a year). Right now the best stuff is only about 5% of this goal. As a comparison, the platinu

        • Well, the other part that's exciting is that GaN is a heavily-studied semiconductor, so hopefully achieving the desired 2% Sb doping won't be difficult. But you're right, theoretical papers like this are a dime a dozen.

  • Not the answer... (Score:3, Insightful)

    by RobinEggs ( 1453925 ) on Wednesday August 31, 2011 @12:39AM (#37261674)
    I know we're supposed to love all technological solutions for our energy problems, but I'm just not convinced anymore.

    When I look at how badly most things are managed, at the ignorance and greed that rule the world, I'm quite convinced that properly implementing what we already know could solve more problems than inventing further methods and discovering new things. In everything from energy policy to urban planning to human health we could achieve an almost paradisaical state if we just chose to do those things correctly that we already know how to do correctly and assisted the entire human race in doing the same.

    I'm not advocating cultural imperialism here, I'm just there's plenty of universal ground on which to share with any persons or cultures easily implemented, universally agreeable methods.
    • People deciding to be calm and logical and sacrificing for the good of humanity as a whole? (The opposite of the ignorance and greed and fear we see all around us.) Or some guy in a lab coat eventually inventing a quick technical fix?

      Personally I think cold fusion (or a similarly improbable technological breakthrough like the sunlight->metal->hydrogen described in this article based solely on computer simulation) is by far the more likely of the two possibilities, so I find joy in reading stories lik
      • Cold fusion violates a *huge* amount of experimental data, not to mention a ton of theory that also has a huge amount of experimental data. The original claims where never even verified or duplicated. It was always bogus.

        We already have materials that do this water to hydrogen conversion, they just are not very efficient. Also guess how lasers, transistors, Solar cells etc are designed? By simulation. More or less. And they work pretty closely to the models.
    • This is a great point. Innovation is great, but at some point one has to wonder, is it really about innovation anymore? It's similar to starvation. It isn't that we don't have food. The problem can be political/socioeconomical.

      We need to figure out how to get existing innovation to where it is needed. We already have plenty of technical answers. But maybe the real questions that need answered right now are not technical.

    • by dbIII ( 701233 )
      That is true but it means less beef and bacon because that's not a good way to manage resources.
      On the bright side, they guys that said in the 1970s that the world would run out of food by now were correct given what was going on at the time. However China got their act together after Mao died and went from a pending train wreck to an exporter of food. Without greater improvements in agriculture than we currently have we are apparently facing a crisis some time in the next few decades whether oil prices g
  • by currently_awake ( 1248758 ) on Wednesday August 31, 2011 @12:41AM (#37261688)
    We've used solar power to split water into hydrogen for decades, what matters is cost. How does this compare with standard solar splitting based on surface area? Do you need a crystalline structure to work? Given that raw silicon is more common and more used I expect it's much cheaper. The article talks about semiconductors so it probably needs a crystal structure (drives up cost), so even with better efficiency (single step vs multi step splitting) it's still probably more costly.
  • GaN is expensive (Score:5, Interesting)

    by Anonymous Coward on Wednesday August 31, 2011 @01:05AM (#37261790)
    Gallium nitride (GaN) is used to make blue LED chips, typically vacuum deposited on top of sapphire wafers. While it is a very good semiconductor, it is an order of magnitude more expensive than silicon wafers. Unless there is a huge breakthrough in mass manufacturing cheap GaN wafers, it will be much cheaper to use silicon solar cells to generate electricity and electrolyze water with it.
    • True, but the LED guys are all busting their asses to find a cheaper substrate, and I've seen a few academic blurbs (not unlike this one) suggesting that some material or another looked "promising".

  • Efficiency? (Score:5, Interesting)

    by rthille ( 8526 ) <web-slashdot AT rangat DOT org> on Wednesday August 31, 2011 @01:11AM (#37261810) Homepage Journal

    Does the paper talk about the efficiency of this solution vs Photovoltaic panels and electrolysis? If the hydrogen and oxygen would be split over a large area (say a roof or larger), how would the gasses be collected? It sounds like an interesting result, but not so practical in application...

    • Re:Efficiency? (Score:5, Interesting)

      by c0lo ( 1497653 ) on Wednesday August 31, 2011 @02:09AM (#37262018)

      It sounds like an interesting result, but not so practical in application...

      What's worse that this: based on the abstract [], all they did is to theoretically compute the composition required to lower the bandgap from 3.8 eV to a 2eV required to split the water. Since not yet realized in practice, lots of other things are not (yet) known:
      1. efficiency (including the problem of keeping off the recombination of H and OH that most probably result)
      2. stability to corrosion
      would be the first two to pop into my mind.

  • by jwold ( 124863 ) on Wednesday August 31, 2011 @01:53AM (#37261966)

    2 weeks ago this same source reported on research at the PNWNL [] that uses a Nickel catalyst for a 1000x improvement over the platinum catalyst process now used, for example, on the ISS.

  • by Animats ( 122034 ) on Wednesday August 31, 2011 @02:13AM (#37262024) Homepage

    It uses gallium, which also makes great solar cells, more efficient than anything else. But the cost of gallium solar cells is so high that they're only used on spacecraft. They're about 3x more efficient than silicon solar cells, and 300x more expensive.

  • Um... [] "ScienceDaily (Feb. 20, 2008) — Purdue University engineers have developed a new aluminum-rich alloy that produces hydrogen by splitting water and is economically competitive with conventional fuels for transportation and power generation. "We now have an economically viable process for producing hydrogen on-demand for vehicles, electrical generating stations and other applications," said Jerry Woodall, a distinguished professor of
  • How hard is it to then separate the hydrogen and oxygen gasses that are produced?
    • Well, I guess you let them "settle" and the hydrogen will rise to the top where it can be pumped off and compressed. Presumably the oxygen can be bottled as well, though I expect demand for it is lower. I imagine more oxygen in the atmosphere is a good thing, right?
  • by kobaz ( 107760 ) on Wednesday August 31, 2011 @07:28AM (#37263064)

    I don't see anyone else mentioning this... but isn't hydrogen explosive? []

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