A team of scientists at the Massachusetts Institute of Technology has developed what it describes as the first practical artificial leaf. The device, made from silicon, electronics and catalysts, is the same size and shape as a playing card, but thinner. It splits water into its two components, hydrogen and oxygen. These are then stored in a fuel cell and used later to generate electricity. “It’s really cool stuff — they’re taking a solar cell and turning it into a battery,” Carl Howe, director of anywhere consumer research at the Yankee Group, told TechNewsWorld.
this other article implies that the leaf itself is highly effective and produces the current to produce O2 and H2 from the water..
http://www.wired.co.uk/news/archive/2011-03/28/artificial-leaf
a google search with "artificial leaf MIT" brought several links
Richard is correct: where is the electricity to generate electrolysis coming from? Is the leaf itself generating electricity?
I hope SO can answer this question.
Also how does the leaf produce electricity at night?
So this has been an excellent description of a novel catalyst for electrolysis. Where is the solar part of this? Sounds to me like this "leaf" already assumes you have electricity. In any case, at 100mA/sq. cm, assuming you need about 2.5V of potential in the presence of this catalyst, you need about 2.5kW of power per sq. meter. At 1000mA/sq. cm, you need 25kW. Bummer that the entire electromagnetic spectrum of the sun falling on the Earth is only about 1kW per square meter. Guess this might be a good solution for Mercury. Sorry. Forgot. There's no water there.
The real problem is getting that tiny 1kW/sq. meter from photons streaming in from the Sun to an electrical current. The best technology available can currently transform about 25% of that power, at extreme cost. This device apparently does nothing for that process, but assumes the electrical current already, and simply performs the hydrolysis after the fact. This is a great advancement for the hydrogen fuel industry, but mentioning the word solar at all in this article is disingenuous. The electricity to power this device will almost certainly come from coal or nuclear.
So you have this leaf floating in water bubbling away hydrogen and oxygen. The hard part is going to be collecting those gases and recombining them in some kind of fuel cell. Maybe a vat of leaves in a centrifuge to separate the gases? Hydrogen is still explosive (see Fukishima Dai Ichi). Lots of problems still to be solved. Excellent first step.
Loading ...
Power Plant: One Small Leaf Could Electrify an Entire Home
Posted by: Richard Adhikari March 28, 2011 12:20 PMA team of scientists at the Massachusetts Institute of Technology has developed what it describes as the first practical artificial leaf. The device, made from silicon, electronics and catalysts, is the same size and shape as a playing card, but thinner. It splits water into its two components, hydrogen and oxygen. These are then stored in a fuel cell and used later to generate electricity. “It’s really cool stuff — they’re taking a solar cell and turning it into a battery,” Carl Howe, director of anywhere consumer research at the Yankee Group, told TechNewsWorld.
http://www.wired.co.uk/news/archive/2011-03/28/artificial-leaf
a google search with "artificial leaf MIT" brought several links
I hope SO can answer this question.
Also how does the leaf produce electricity at night?
http://www.ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr20110203-00
However even though it can rearrange itself back to order, I wonder about the constituents degrading over time.
So this has been an excellent description of a novel catalyst for electrolysis. Where is the solar part of this? Sounds to me like this "leaf" already assumes you have electricity. In any case, at 100mA/sq. cm, assuming you need about 2.5V of potential in the presence of this catalyst, you need about 2.5kW of power per sq. meter. At 1000mA/sq. cm, you need 25kW. Bummer that the entire electromagnetic spectrum of the sun falling on the Earth is only about 1kW per square meter. Guess this might be a good solution for Mercury. Sorry. Forgot. There's no water there.
The real problem is getting that tiny 1kW/sq. meter from photons streaming in from the Sun to an electrical current. The best technology available can currently transform about 25% of that power, at extreme cost. This device apparently does nothing for that process, but assumes the electrical current already, and simply performs the hydrolysis after the fact. This is a great advancement for the hydrogen fuel industry, but mentioning the word solar at all in this article is disingenuous. The electricity to power this device will almost certainly come from coal or nuclear.