A practical artificial leaf that can turn sunlight and water into energy as efficiently as the real thing has long been a Holy Grail of chemistry, and researchers at MIT may have finally done it. Today at the National Meeting of the American Chemical Society researchers from MIT's Nocera Lab, led by Dr. Daniel Nocera, claimed that they've created an artificial leaf made from stable and--more importantly--inexpensive materials.
The artificial leaf looks nothing like the natural leaf that it mimics, but its inputs and outputs are the same. Made of silicon, electronics, and various catalysts that spur chemical reactions within the device, the artificial leaf uses sunlight to break water into hydrogen and oxygen which can then be used to create electricity in a separate fuel cell. Placed in a gallon of water and left in the sun, these artificial leaves could provide a home in the developing world with basic electricity for a day, Nocera said.
The Nocera Lab's artificial leaf, it should be noted, isn't the first working attempt at recreating photosynthesis in artificial materials. But previous attempts have led to artificial leaves full of unstable materials that are expensive and lead to short life spans. Nocera and his team identified a set of inexpensive, common catalysts including nickel and cobalt that get the job done with far less expense. And in the lab their playing-card-sized leaves have worked continuously for 45 straight hours without a drop in output.
Nocera and company will next try to boost both efficiency and lifespan of their photosynthetic material. It's still a workbench technology at this point, but the leap forward presented here is significant. Scaled and mass produced, something like the Nocera Lab's leaf could be the key component to shifting toward a hydrogen-based economy. In the nearer term, such technology could at the very least power parts of the globe that are currently off the grid with clean, plentiful, and easy-to-come-by energy.
I wonder what an electronic cell looks like?
Besides, I've got this idea that the key to living without plants is to create artificial plants. All of my craazy ideas are being made real! Is that a good thing or a bad thing for me?
At least now the tree huggers cant cry about deforestation since real trees are no longer necessary. I can't wait for the day when they send millions of these leaves to Mars to create oxygen from the tons of frozen water stored under the surface.
they could only fully replace trees if they self-replicated, and were edible, as well as producing fruit. lets face it, this is a great imitation, but it is nowhere near as efficient as the real thing. especially since these only last 45 hours, but the real ones can last just less than a year.
If your talking about leaves they can last for decades-centuries. But if your talking about trees, they can last for millenia. Am I right?
I was talking about the leaves, and how on most trees, they drop off every fall, lasting less then a year, and most trees do have undefined life spans.
Great stuff. Now if they could also self-replicate and self organize their electric connections, we're all set.
It would even be nicer if they came in pleasing shapes, just like natural leaves. I can't see them wasting the green part of the spectrum though, so will these leaves be a dull, dark gray color?
Also, how about having them use atmospheric water vapor in high-humidity environments?
"The artificial leaf looks nothing like the natural leaf that it mimics, but its inputs and outputs are the same...the artificial leaf uses sunlight to break water into hydrogen and oxygen which can then be used to create electricity in a separate fuel cell"
...and it acts nothing like the natural leaf that it mimics. Last time I checked, leaves did not brake water into oxygen and hydrogen.
tell me how they use hydrogen and oxygen to make simple sugars then?
Because they also include Carbon - a key components of sugars (sucrose, fructose, glucose, etc).
This splits H2O into 2X H2 and 1X O2.
Plants take H2O and CO2 to create sugars (C6H12O6 and others) and a net out put of 6X O2 in waste oxygen.
Thus, this process could never replace photosynthesis for Carbon absorbtion or Oxygen production.
Oakspar is that to me or Capt_Tight_Pants, because that validates my statement, plants break H2O into hydrogen and oxygen to bind them with carbon, and the out put of oxygen,agreed this synthetic plant can't replace the prodction of sugar synthesis it still creates hydrogen and oxygen, probably with a net out put of H2) from the fuel cell, Capt_Tight_Pants is still wrong in that plants don't split H20
Once, when studying the evolution of early plants it was explained to me that photosynthesis in modern plants is relegated ( presumably by evolutionary pressure) to wavelengths of light that are poorly suited to photosynthesis.
In other words blue appearing leaves or red appearing leaves ( not when dead) could have been much more efficient at converting sunlight into sugar. The green leaves we are used to won out over time for some reason. This doesnt mean other wavelengths are not more efficient than others. So does anyone know if these artificial leaves are designed to take advantage of more efficient wavelengths of light?
Glad we are smarter than guys and gals at MIT.
I looked at the original article and it stated that the artificial leaf was 10 times more efficient than the natural one. Is it because the artificial leaf is making electricity directly and not making starches and sugars?
@Delkomatic the argument isn't against the usefulness, but against the implication that 'we don't need trees afterall.'
I'd say the most important "input" of a natural tree is CO2... the artificial leaf doesn't seem to act as a carbon sequestering system... (so obviously can't replace trees).
Still an amazing breakthrough though!
So many posts about making "leaves". Doesn't anyone see that's not the point? The point is make energy more efficiently and with a built in storage system.
Now what I would really like to know is what do they think the electrical use of a house in a "developing country" is? For all I know that might be that might be a 15 watt light bulb. It would be nice if they gave the power output in some unit you can get a real feel for.
"Placed in a gallon of water and left in the sun, these artificial leaves could provide a home in the developing world with basic electricity for a day"
Hopefully the leaf can function in dirty or salty water. Not many homes in the developing world can spare a gallon of clean water a day.
So true Wootyman, Some people would much rather have the water then the power.
Yep, ditto Wooty. How much water will it need to power a non-3rd world home? Water is quickly becoming more and more valuable. Aquifers are already running down, etc...
Then again, Hydrogen combustion forms hydrogen oxide or water vapour, so can it be used to create more water and thus more hydrogen and more water and more hydrogen? All facilitated by the sun?
If I’m not entirely mistaken, a fuel cell which utilizes hydrogen as fuel recombines hydrogen and oxygen in the form of water vapor in its process of generating electricity. The leaf is simply using solar energy to perform electrolysis. So really it could be somewhat self perpetuating if cooling down the water vapor was incorporated in the system. I’m just a cook, so don’t bash me too badly.
you guys should notice "then be used to create electricity in a separate fuel cell",so I think this artifical leaf can't product electricity iteself.
After jotting down all my ruminations and ponderings on this new technology, I soon had a page and a half and realized that it’s not really worthy of a “Comment”. So I’ll summarize.
There was a recent interview with Dr. Daniel Nocera on NPR radio that you can easily find if you care to listen to it. As far as output is concerned, Nocera claims that an average North American home in the United States and Canada consumes about 20 to 30 KWH’s in a 24 hour period. Further, an average home whose roof is covered in these “Leaves” would be capable of producing that kind of energy using approximately 4 liters of water. Combining this technology with a separate fuel cell would create a closed system in that the original 4 liters of water could be recovered and reused.
As pointed out in the article and by other posters, the current technology is only useful for about 45 hours of conversion before the “Leaves” need to be “Recharged”. Presumably the catalysts used to speed the conversion process are consumed and need to be replaced before continuing. This is not conducive to mass consumption. The “Lifespan” of the leaf would need to be pushed out much further.
Not pointed out in the article, the NPR interview or by other posters as of yet is that this does not sound like a truly renewable source of energy. I don’t think we have worked out a “perpetual energy machine” here just yet. The catalysts, Nickel and Cobalt, are “Cheap and readily available”. Yea for bench top testing I can agree with that. However if this is going to go Global and be consumed in global quantities, just how much of a supply do we have exactly? What are the costs of gathering and refining these materials? What is the cost of “Recharging” the leaves with this material? Presumably the Nickel and Cobalt are “Consumed” in the initial conversion process. What is the byproduct? We have not figured out a way to “Destroy Matter” here, so something must be left behind. Is it reusable? Is it toxic? What are the costs of refining it or disposing of it?
Ultimately this technology sounds promising and VERY exciting. As a nation Id like to see this technology heavily invested in, in terms of research and development. If all the kinks can be worked out, this could be our nation’s future. This technology has the potential to impact every single aspect of modern life. The number of jobs that could ultimately be created by this is off the charts. Its potential uses are equally off the charts. If I were king of the U.S.A. Id make this a topic of daily discussion and focus. This is a basket truly worthy of investing a lot of resources in.
Everyone who seems concerned that it "ONLY WORKS FOR 45 HOURS"...
If you read the article linked, you will see that...
"In laboratory studies, he showed that an artificial leaf prototype could operate continuously for at least 45 hours without a drop in activity."
He only tested his prototype for 45 hours. He doesn't know how long it COULD work for... just that it def. works for at least 45 hours.
If I ran my car for 5 minutes in my garage, I'd say "well, it def. runs for at least 5 minutes on the amount of fuel in the gas tank."
That does NOT meant it's the "limit" on how long it can work, just the amount that was tested...
Taken directly from the article, and the next sentence below what you are quoting.
"Nocera and company will next try to boost both efficiency and lifespan of their photosynthetic material. It’s still a workbench technology at this point,"
Maybe you are accurate in your assessment of the sentence you are quoting.
However I think point to be made here is that regardless of just how long the prototype "Could" run in its current state, it's still far to short of a time to be commercially viable. I'm personally thinking what, maybe a year between needing to recharge the Leaves? Even longer depending on how much it would cost to recharge or replace them. Maybe 2 years? Three years? More? My interpretation of the article says that they are no where near being ready to go commercial on an "Industrial" scale. It's one thing to be able to use this technology to supplement your power consumption. However the true potential of this technology won't be unlocked until they can greatly increase the life span of the "Leaf" such that you could completely disconnect from the grid. The longer you can push the lifespan of the “Leaves” out, the more potential you unlock. I can envision Oil Refinery sized operations using this technology to produce hydrogen fuel like they do gasoline today. However for operations of that scale to be viable, you're not going to be able to change the “Leaves” out every few days. Imagine being able to distill sea water into pure drinking water using this energy source. Can you even imagine the implications?
It is a catalysts nature to be consumed in the chemical reaction it takes place in. It's reasonable to assume that they have not yet discovered a way to push the longevity of the catalyst out to a truly meaningful lifespan yet. Or for that matter if they can find a catalyst that is renewable and sustainable. But if and when they do figure this out, I believe that it will be one of those watershed moments, where everything is either compared to what came before or what came after it. Simply amazing.
Generally catalysts are not "consumed" doing the work they do, facilitating reactions. The reason they often decrease in efficiency is that they get dirty or contaminated or coated with something. The innovation here is that, compared to the previous artificial leaf, which used expensive catalysts, that were not very long lived, this cheap catalyst is much more stable. It still needs to be improved, but that now seems achievable. The thought that a few card sized cells floating around in a few liters of water sitting out in the sun could power an average home is crazy. The operating cells will still have to be like solar arrays, covering many square meters, like most of your roof. The cells would be sealed and have the water as a thin film covering the cells, and the produced hydrogen would be come off the top of the cells. That's where the idea of a few liters could produce the energy, as a thin film. Hopefully the oxygen is produced separately from the hydrogen, and is pulled off separately(if not, they are fairly easily separated with semipermeable membranes). The hydrogen and oxygen are then piped down to a fuel cell, to generate immediate electricity, or stored in a tank of hydrogen adsorption media, like they now have for hydrogen powered cars, to be used when the sun don't shine.
Real trees and plants are still needed. This is just another step into the future.
*D Ace Lee*
Fascinating invention! I can see the day when our Prius's will be covered in foliage...
Wow, Trees useless? Trees help prevent soil erosion and wash-off. Or do you think that farming is useless now with the ability to synthesize food?
I heard it was economically viable and was 10x better than a real leaf
anyone seen this new techblog at www.regiz.blogspot.com?
seems cool to me
Its pretty cool