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  (Source: Meyer Group)
Future dye-based electrochemical cells may reach efficiencies of up to 15 percent, team says

The top 1 percent gets it all.  No we're not talking about America's income gap, we're talking about a tantalizing, but still rather inefficient method of solar power grid storage -- hydrogen.
 
I. Solar Storage -- A Big Problem
 
One of the toughest problems of the alternative energy industry is the question of variability.  While utilities can control when to burn fossil fuels, to directly satisfy demand, we can't control when the sun is shining or the wind is blowing.  A possible solution is to store the energy, either chemically or mechanically.
 
Much of the early work has focused on grid storage using spent electric vehicle batteries.  But given the low levels of EV sales and distribution difficulties, this method can't fully satisfy the power demands of millions of Americans at present.  Compounding that method’s flaws is the fact that these aren't very good storage devices anymore in the first place -- hence why they've been declared "spent."

Solar storm
Solar is a tantalizing, but inconsistent power source. [Image Source: NASA]

Many have suggested that we break water into diatomic oxygen molecules and hydrogen; plants do this as a precursor to sugar production during photosynthesis.  One way to do this is to harvest the solar energy as electricity and then perform on-demand hydrolysis.  Energy losses on the PV end are already bad and since most solar cells degrade or short in water, they become worse as you have to transfer electricity out of the solar cell and into an electrolysis device.  In short, the compounding losses mean it takes a lot of electricity to produce a little hydrogen.
 
An alternative method is to use water-soluble catalysts  -- chemicals that speed up chemical reactions by reducing the energy barrier that a series of reactants must overcome to transform into a series of products (in this case pure hydrogen and oxygen fuel).  To do this you would generally use a chromophore-catalyst -- a catalyst activated by light -- to drive the reaction.
DSSC
Catalysts can rip electrons away from water to produce storable hydrogen fuel.
[Image Source: Meyer Group]

Chromophore catalysts operate by ripping electrons away from a compound such as water, which creates a flow of current that can be used to drive electrochemical reactions (e.g. water splitting).  As this process is all localized, theoretically you could minimize losses much more than in an approach relying on standard cells.  Better still, its heavy use of abundant materials like carbon and nitrogen, could  -- in the long run -- reduce costs.

Artificial photosynthesis
Nanoparticle-based systems can create artificial photosynthesis.
[Image Source: The Meyer Group]

Bacteria, protists, and plants have been doing this for billions of years using the chromophore-catalyst chlorophyll to produce electronics, which in turn split water, which in turn is used to produced sugar, the "battery molecule" of the organic world.  But chlorophyll isn't necessarily the easiest molecule to produce; so human researchers have been examining novel chromophores (light absorbing compounds, aka pigments) to alternatively use.

artifical solar
[Image Source: The Meyer Group]

Aside from tuning the pigment, there's a host of other issues including mounting of the pigment to a nanoparticle.  In plants this is done by nanostructures called "thylakoids", which are stacked inside chloroplasts.  Thylakoids vary in diameter, but tend to be around 15 nm thin in higher plants.  A crucial question is how plants "glue" their chlorophyll molecules in place inside the thylakoids; in manmade chromophore-loaded nanoparticles, the chromophores tend to break away, decreasing efficiency and slowly killing the conversion cell.
 
Another key challenge is how to shuttle away electrons to prevent a "traffic jam", electrically.  So long as the charge is being transferred elsewhere, the chromophore-catalyst is free to keep ripping electrons away from water.  But once the chromophore becomes charged, it has to wait for that charge to dissipate before continuing the process.  Again, understanding of how the charge transfer occurs in plants is a topic of ongoing research.
 
But in terms of synthetic analogs to the plant's stacked thylakoid energy storage system, researchers are making significant advances to overcome these problems, using common nanomaterials.
 
II. The First Fully Manmade Photosynthesis Device
 
A team of researchers led by the University of North Carolina - Chapel Hill campus (UNC-Chapel Hill) Professor Tom Meyer and North Carolina State University (NCSU) Professor Gregory Parsons, have used a complex nanostructured material to capture 1 percent of the energy in the sunlight received.  That's far worse than the average last year for conventional panels -- 15 to 16 percent (according to estimates by Forbes).  With some premium cells hitting efficiencies of 21+ percent, 1 percent just isn't cutting it.

Professor Thomas Meyer
UNC Professor Thomas Meyer [Image Source: Auburn.edu]

On the other hand the result is far better than past chromophore catalyst results, and the faculty members are convinced they can achieve even better.

Professor Meyer comments:

When you talk about powering a planet with energy stored in batteries, it’s just not practical.  It turns out that the most energy dense way to store energy is in the chemical bonds of molecules. And that’s what we did – we found an answer through chemistry.

Splitting water is extremely difficult to do.  You need to take four electrons away from two water molecules, transfer them somewhere else, and make hydrogen, and, once you have done that, keep the hydrogen and oxygen separated. How to design molecules capable of doing that is a really big challenge that we’ve begun to overcome.

So called 'solar fuels' like hydrogen offer a solution to how to store energy for nighttime use by taking a cue from natural photosynthesis.  Our new findings may provide a last major piece of a puzzle for a new way to store the sun’s energy – it could be a tipping point for a solar energy future.

To attain the current results Professor Meyers began by hunting for manmade chromophores that could absorb visible light.
 
He found a perfect candidate in a molecule with a number of aromatic nitrogen-carbon rings (bipyridine) mounted to a ruthenium metallic center.  The organic compounds act as the "antenna", while the ruthenium acts as the "signal processor", converting the solar energy into electron flow.  Professor Meyers named the compound "the blue dimer".  Published in the peer-reviewed ACS journal Inorganic Chemistry in 2012, this was a crucial work as it was the first time man had found a synthetic chromophore-catalyst for water splitting.
 
Prior to that work some researchers had managed to achieve similar results -- but not from manmade compounds (they tricked viruses into acting as organic equivalents to the manmade blue dimer).  Other solar cells were merely made to mimic the look of the leaf, for efficiency reasons, but chemically were still traditional thin-film photovoltaic cells.


blue dimerruthenium
[Image Source: The Meyer Group]

Then in 2012 through late last year, Professor Meyers put the new catalysts and its derivatives to use, mounting them to nanoparticles of indium tin oxide (nanoITO).  The group's latest work, for example, uses (PO3H2)2bpy)2Ru(4-Mebpy-4-bimpy)Rub(tpy)(OH2)]4+ catalyst molecules mounted to the nanoparticle.
 
The result was the first "Dye Sensitized Photoelectrosynthesis Cell (DSPEC)".  Unlike the similar "Dye Sensitized Solar Cell" (DSSC), which produces current and potential (electricity), the DSPEC directly produces stored energy in the form of chemical fuel (hydrogen).
Ruthenium chromophoreRuthenium chromophore
[Image Source: The Meyer Group]

But as huge of an advance as this was, the previously mentioned problems rendered it essentially a theoretical curiosity; the cells produced little hydrogen.  The problem was two-fold; the blue dimer loaded nanoparticles needed a better glue to keep the pigments from floating away and they needed a way to enhance transport of electrons out of the pigment and into the nanoparticle.

III. From Curiosity to Contender

Professor Parsons proposed a solution to both issues -- "spraying" the nanoparticle with a thin film of metal oxide.  Films of so-called "transport conducting oxides" (TCOs) TiO2, ZrO2, and SnO2 were evaluated.  His lab found that the best results in terms of electron transport and pigment adhesion came from the titanium oxide films, which also happened to be a relatively cheap ingredient to use (TiO2 nanoparticles are widely used in sunscreens).
artificial water splitting
Then fresh layer of metal-oxide increases the electron transfer from the chromophore "antenna". [Image Source: Meyer Group]

With the gathered electrons, further electrolysis is possible by funneling the electrons to a platinum electrode.  This dual-approach strategy
 
The approach improved the efficiency of the cell to about 1 percent of the incidents solar energy striking the cell, or about 4.4 percent (at maximum) of the absorbed solar energy.  Crucially, it also greatly enhanced the cell longevity.

scaffold
An illustration of the new coated nanoparticle [Image Source: Parsons Group]

Professor Meyer and his colleagues (including Professor Parsons) are currently working in a variety of directions to try to refine the organic electrochemical reaction.  They're examining better substrates (they're currently using poly(methyl methacrylate) (PMMA) and SiO2 sol-gels), on which to adhere the pigment-loaded nanoparticles.  They're examining more complex chromophore compounds, such as protein-like polymers with pigment side chains.  They're also looking at more novel coatings.

ruthenium peptide
Mounting the chromophores to peptide backbones could improve efficiencies.
[Image Source: Meyer Group]

The collaborators feel confident they can boost their efficiencies to around 15 percent.
 
That's a pretty ambitious goal, but if they can achieve it and find a way to produce their catalyst compounds inexpensively (perhaps with genetically engineered helper-microbes) it would be a game changer for solar.  No longer would solar be plagued by variability or use of expensive rare earth metals storage devices; solar would be on more of an even footing with other non-fossil fuel energy solutions such as algal biofuels and clean nuclear power.

artificial solar
An artist's rendering of the catalyst mounted to the coated nanoparticle [Image Source: Meyer Group]

The pair's latest work can be found in a pair of papers -- one published in the Oct. 2013 edition of the prestigious peer-reviewed journal PNAS, and another published in the Nov. 2013 edition of the journal.  The work was funded, in part, by grants from the U.S. Department of Energy (DOE).

Sources: UNC, NSCU





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RE: Proof
By Reclaimer77 on 1/16/2014 11:12:28 PM , Rating: 2
What the greens don't get is that there's no need to force market manipulation when it comes to energy. As traditional sources become harder to get, and more expensive to utilize, alternatives will be researched farther and become more viable.

This is how markets work. But these idiots honestly think the world is just going to sit on it's ass until one day all the oil or whatever runs out. Like it will be a big surprise, and we'll just be caught flat-footed with no options.

Hydrogen and biofuels, I believe, will be a reality in the near future. It's just a technology problem today, and those ALWAYS get overcome. And who knows? Fusion could come soon after.


RE: Proof
By homebredcorgi on 1/17/14, Rating: 0
RE: Proof
By Reclaimer77 on 1/17/2014 12:07:11 AM , Rating: 1
quote:
They want alternatives because of concern of climate change


Yeah like I said, they're idiots.


RE: Proof
By BSMonitor on 1/17/2014 9:55:44 AM , Rating: 4
LMAO, and Reclaimer knows idiot


RE: Proof
By 1prophet on 1/17/2014 12:42:29 PM , Rating: 2
quote:
They want alternatives because of concern of climate change (I know, a dirty word on this site) not because they think the world will turn into Mad Max when the oil runs out!


If instead they sold it as being independent and freedom from the oil companies even though it may be more expensive, alternative energy would be much further along today.


RE: Proof
By troysavary on 1/17/2014 4:23:26 AM , Rating: 3
I'm not holding out much hope for fusion ever becoming viable. But it doesn't matter. There is still so much untapped potential in fission. All the "spent" fuel still contains vast amounts of untapped energy. There are new reactor types that can use the fuel rods from older reactors.

On top of that, there is thorium, which is abundant in coal. Right now, burning coal releases radioactive thorium into the air. Extracting the thorium is energy intensive, but in the process, it converts the coal into a more oil-like form. The other plus is that once we start using the extracted thorium in reactors, then the process can become energy positive. There should be more than enough energy from the thorium reactor to refine further coal.

Just build thorium reactors at large coal deposits. They can be used to power the extraction process, and the excess energy goes into the grid. And you have, after it is all said and done, oil that can be refined into other hydrocarbon products. The situation is win all around. Which is why current governments will probably never ok it.


RE: Proof
By troysavary on 1/17/2014 4:39:57 AM , Rating: 2
To add more on thorium, it is safer. Thorium reactor can produce a chain reaction and therefor cannot meltdown. Not that meltdowns are a danger in any modern reactor design, but the public perception is still there. Thorium does not, in its natural form, contain enough fissable material to sustain a reaction, but when enriched with 10% plutonium, will start a fission reaction. So it has the added benefit of using up the plutonium by-product of uranium reactors. After the plutonium is spent, there is enough of the fissable thorium isotope left for this spent fuel to be used in a second stage reactor.

Thorium is abundant, with an estimated amount that puts it near lead in commonness. It is fairly cheap as well. There are enough known thorium deposits to last for millennia. Plus, once they tell the general public the element was named after Thor, people will probably think it is some sort of alien tech and be all for using it.


RE: Proof
By ClownPuncher on 1/17/2014 3:05:48 PM , Rating: 2
If they helped pay rent and property taxes, I'd let them put a thorium rector in my back yard.


RE: Proof
By ClownPuncher on 1/17/2014 3:06:36 PM , Rating: 2
*reactor.


RE: Proof
By MrBlastman on 1/17/2014 3:12:32 PM , Rating: 2
It'd help pay for your heating bills, too!


RE: Proof
By MrBlastman on 1/17/2014 10:13:24 AM , Rating: 2
I think for fusion to become viable we'll need to have the ability to create a gravity well deep enough to force quantum irregularities that actually allow it to occur deep within the sun.

We're a long way away from that. We don't even know exactly what gravity is because, well, we don't know what "nothing" is yet.

And besides, when we DO figure all that out, we won't even need the Earth anymore as a primary residence. We'll be able to hop-scotch across the Galaxy at that point (well, with limitations).


RE: Proof
By BSMonitor on 1/17/2014 9:54:06 AM , Rating: 1
quote:
and those ALWAYS get overcome.


"And in the meantime, you all with your hundreds of millions of gasoline engines.. You just sit on your ass and starve until we get that figured out.."

Bend over, you are about to take my c%ck again.

Wait until the traditional sources are harder to get?? We tried that. We spent 10 years in Iraq. Killed hundreds of thousands of people so your ignorant mommy tit sucking ass can have cheaper gasoline... For the moment.

Reclaimer == continuing to sound like a child spoiled on mommy's tit milk == winning at life.


RE: Proof
By MrBlastman on 1/17/2014 10:09:46 AM , Rating: 2
Your eloquence eludes you. Three and four letter words do wonders for bolstering your intelligent image.


RE: Proof
By ClownPuncher on 1/17/2014 7:24:04 PM , Rating: 2
Balls ass wankfoam


RE: Proof
By MrBlastman on 1/17/2014 11:07:55 PM , Rating: 2
:)


RE: Proof
By troysavary on 1/17/2014 2:07:50 PM , Rating: 2
Yet, none of the oil fields went to Americans. But never mind that. Keep up with your delusion that the Iraq war was about oil.


RE: Proof
By Reclaimer77 on 1/17/2014 4:18:06 PM , Rating: 2
I love how he claims we got "cheaper" gasoline out of the wars. Uhhh hello?

The entire region got, predictably, destabilized. Gas prices spiked and never recovered.

Oh I forgot, that was also part of the evil Bush/Cheeny Halliburton conspiracy! To err oil..more money and ummm stuff.


RE: Proof
By Rukkian on 1/17/2014 10:46:24 AM , Rating: 2
While I think some are over the top with pushing their agenda (which side is not?), There is more to it than just "letting the markets work". Most corporations will not invest in something that may work out 20 years from now. Corporations are run by stock holders who typically want a fast buck and more immediate profits. Without some forward thinking, and money put into longterm R&D, at some point we will be even more beholden to our Chinese masters. Other countries will have the tech, and while our government has ways to "borrow" some of that tech, we do not want to be behind many other countries just because of a few narrow minded, stick our heads in the sand people did not think we should be investing in our future.


RE: Proof
By Reclaimer77 on 1/17/2014 10:54:20 AM , Rating: 2
There are corporations out there who do nothing BUT research this stuff. What are you talking about?

We'll be fine, really.


RE: Proof
By Rukkian on 1/17/2014 2:39:47 PM , Rating: 2
And how many of these corporations do this just out of the goodness of their hearts with no government help?

Maybe I am wrong, and every corporation out there is currently spending billions and billions to research things that if they work will only do a payback in 20-30 years, but I doubt that. I would guess that if any actually are, they are doing it with government grants of some sort. Since you are completely against any government intervention, can you list a few of these corporations?


RE: Proof
By Schrag4 on 1/23/2014 12:58:10 PM , Rating: 2
Sorry to jump in like a week later, but...

quote:
And how many of these corporations do this just out of the goodness of their hearts with no government help?


Well, today, since it's not viable, these corporations would have to rely on people like you who believe this is an important thing to do right now for their funding.

As has already been pointed out, though, the decades leading up to a shortage in fossil fuels will see a necessary rise in prices for those fuels. Are you telling me that these corporations won't be able to fund their research when oil prices increase ten-fold per decade for 3 or 4 decades? It won't be sudden , and when it happens, alternatives will become be viable automatically. Any funding for alternatives up until that point will have been at least partially destructive of wealth, as funding for alternatives after that point will flow freely, without even needing the force of govt to make it happen.


RE: Proof
By Mint on 1/18/2014 2:17:37 PM , Rating: 2
Nuclear power wouldn't exist without government support, and I'll bet anything that it'll become the most economical energy source of the future. You're pro-nuclear, aren't you?

There's a reason that most research is publicly funded: It's impossible for any company to be the sole beneficiary of that research. Any attempt to own knowledge like that would make our patent system even more broken.

Hydrogen doesn't have any technology problems. We can make the fuel cheaper than gasoline, and we've known how to use it in engines for decades. Its problem is volumetric density, which is fundamental to hydrogen itself, and infrastructure, which is a gargantuan chicken-and-egg problem that the free market will never solve by itself (EV's infrastructure issues are orders of magnitude smaller due to home charging).

GTL and other synthetic fuel processes are much more economically viable than large-scale biofuels.


RE: Proof
By Reclaimer77 on 1/18/2014 8:48:38 PM , Rating: 2
quote:
Hydrogen doesn't have any technology problems.


Conflicts with:

quote:
Its problem is volumetric density, which is fundamental to hydrogen itself


How is that not a technology problem? Figuring out the density problem absolutely requires technology to solve. It's not going to grow on trees!

You know what, you don't ALWAYS have to make yourself sound superior in all matters to discuss something. It just comes off smug.

quote:
Nuclear power wouldn't exist without government support


And it wouldn't exist without the free market either. Dude the Government can't even get a goddamn WEBSITE to work right! You think we would have viable nuclear power without the private sector?

quote:
GTL and other synthetic fuel processes are much more economically viable than large-scale biofuels.


Interesting you brought this up. Shell has spent about $25 billion of it's own money researching and building GTL plants. And that's just one company. But oh yeah, only the Government spends money on research...


RE: Proof
By Mint on 1/22/2014 8:37:49 AM , Rating: 2
quote:
How is that not a technology problem?


You expect technology to change fundamental properties of matter? BMW even stored it in liquid state at cryogenic temperatures - the densest for possible - and that still isn't good enough, hence everyone abandoning that approach.

Tell me one thing: How is hydrogen superior over natural gas? You don't believe in GHG anyway.

Pointing out facts is not smugness. You should take these suggestions and do some research for yourself to see if I'm right. Natural gas is the biggest threat to EVs as a cost effective fuel of the future, not hydrogen. Leading biofuel companies like Coskata have jumped ship to focus on GTL.

quote:
You think we would have viable nuclear power without the private sector?


Did I ever claim otherwise? You just assume that I want to eliminate the private sector. Even my idealized economy uses the free market for the vast majority of the economy.

You, OTOH, explicitly said there should be no market manipulation, and under such a mantra, nuclear power would not exist.


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