Posted on 08/12/2009 5:27:17 PM PDT by smokingfrog
Sunlight can readily liberate hydrogen from water as a result of a novel solid catalyst that mediates that reaction with unprecedented efficiency, according to researchers in China who developed the catalyst. The study advances the decades-old search for an inexpensive way to produce hydrogen, a versatile fuel, from water, an abundantly available resource.
A key challenge to tapping into solar energy on a broad scale is developing an effective way to store that energy. One strategy calls for using sunlight to produce fuels such as hydrogen, which in many ways is considered an ideal energy carrier. Using sunlight to evolve hydrogen from water photolytically is one direct route to converting solar energy into fuels. But most photocatalysts suffer from significant shortcomings.
For example, many photocatalysts facilitate water splitting only under ultraviolet light, which constitutes just a few percent of the energy in the broad solar spectrum. Other catalysts have been designed to exploit the visible wavelengths of sunlight. But they do so only with limited effectiveness. A standard measure of that effectiveness is known as quantum efficiency, which can be expressed as the ratio of the number of product molecules to incident photons.
Among synthetic catalysts activated by light in the visible range, the highest quantum efficiency for hydrogen production from water reported until now is about 60%. In contrast, the quantum efficiency of natural catalytic systems that drive photosynthesis can reach 95%.
Now, researchers at Dalian Institute of Chemical Physics, in China, have developed a three-component semiconductor-based catalyst that can produce hydrogen from water when irradiated with light in the visible-wavelength region (420 nm) with a quantum efficiency as high as 93% (J. Catal., DOI: 10.1016/j.jcat.2009.06.024).
(Excerpt) Read more at pubs.acs.org ...
It’s enough to make you want to sing that old hippie tune, “Let The Sunshine In”
This is great news if it’s cheap enough. You could not only generate power with the hydrogen from seawater but you could then use the “ash” as potable water.
Think outside the box even more. If you scattered this stuff on a daylit ocean surface, would it continue to evolve hydrogen which could be lit as a fire?
Interesting. Scientists in Tel Aviv reported a similar result a number of months ago.
ML/NJ
What’s the energy density of hydrogen (any storage system) w/r/t other transportation fuels?
If it’s real, maybe my fuel cell stocks will one day be worth something again.
Pretty darn good, if you can get it to the fusion point! ;-)
LOL, can you do it cold? *\;-)
What can you do with the unidentified sulfur/oxygen stuff, I wonder.
The water must contain significant amounts of sulfur to make the process work. One source could be water from coal slurry pipelines.
Imagine: Reducing sulfur emissions from coal power plants and generating hydrogen at the same time!
as a gas, at 10,000 psi, its about 1/7 the eneergy density of gasoline (seven gallons of pressurized hydrogen would produce the same energy as a gallon of gasoline). As a liquid, is is about double the energy density of gasoline. It has to be very very cold to liquefy at atmospheric pressure.
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