Hydrogen technology has beenpromoted for decades but always ran head on into the intractable problem ofproducing hydrogen itself from any source in a way that was cheap, let aloneever cheaply splitting water.
Suddenly, though we had strongindications about all this last year, we have a cheaply produced artificialleaf that absorbs solar energy to split water and preferentially producehydrogen. This is good enough. Engineering solutions can now follow.
Hydrogen storage now becomes thenext bottleneck. A property happilyproducing hydrogen that can be used for heating needs storage. Converting it into electrical power through afuel cell seems wasteful and an inconvenient step best avoided. Yet, for large installations it is an option.
I see this easily integrated withsolar cell technology were the usable solar portion differs from the usable hydrogenportion. All sorts of clever adaptationssuggest themselves.
Scientists unveil 'world's first practical artificial leaf'
By BenCoxworth
18:02 March 28, 2011
Scientists unveil 'world's first practical artificial leaf'
Leaves – the kind that grow on trees – create energy from sunlight andwater through the process of photosynthesis. For over a decade, scientists havebeen kicking around the idea of creating an "artificial leaf." Such adevice would use sunlight to split water into hydrogen and oxygen, which couldthen be stored in a fuel cell and used to create electricity. A functioningartificial leaf has been created before, but was impractical due tothe fact that it was made from expensive materials, and was highly unstable.Now, however, scientists are reporting that they have created a cost-effective,stable artificial leaf.
"A practical artificial leaf has been one of the Holy Grails ofscience for decades," said MIT's Dr. Daniel Nocera, who led the research team."We believe we have done it. The artificial leaf shows particular promiseas an inexpensive source of electricity for homes of the poor in developingcountries. Our goal is to make each home its own power station."
Nocera's leaf is about the size of a poker card (but thinner), and ismade of silicon, electronics, and nickel and cobalt catalysts – all materialsthat are relatively inexpensive and widely-available. Placed in a gallon ofwater in bright sunlight, it is said to be able to produce enough electricityto supply a house in a developing country for a day. It would be connected to afuel cell located either on top of or beside the house.
When tested under laboratory conditions, it was able to operatecontinuously for at least 45 hours without a drop in activity. Newly discovered nickel and cobalt catalysts are thekey to the leaf's practicality, allowing it to reportedly operate at tentimes the efficiency of a natural leaf. Nocera believes that the efficiency canbe boosted much higher in future versions and has founded a companycalled SunCatalytix to pursue development of the technology.
John Turner of the U.S. National Renewable Energy Laboratory created afunctioning artificial leaf over ten years ago, but it incorporated costlymetals, and barely lasted one day. More recently, Chinese scientists havepresented a designfor an artificial leaf that incorporated titanium dioxide and platinum, andDutch researchers created a light-capturing system based on the chlorophyll of thealga Spirulina.
The MIT research was presented today at the 241st National Meeting ofthe American Chemical Society in Anaheim , California
Nocera discusses the technology in the following video:
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