Skip to main content

Freely Speaking: What is an Artificial Leaf?

It's been a while again since I last posted here. Writing my thesis and preparing for the actual defense in July are taking most of my time. However, I wanted to at least share an interesting idea I came across in the last couple of months before this month is over.

And so today, I'll write about the artificial leaf which Professor Nocera at MIT was researching. It's been all over the science news: an alloy made of nickel and cobalt acts as a catalyst to split water into hydrogen and oxygen similar to what plant leafs do when they perform photosynthesis.

After the coolness of the words "artificial leafs" wore off, I started to wonder what is so special about an artificial leaf. After all, doesn't an artificial leaf just do electrolysis? Couldn't I just achieve the same by connecting solar panels to a container with water and two electrodes?

Apparently, the answer is yes and no. By applying a current to water, electrolysis could indeed be performed producing oxygen and hydrogen. The current produced could even come from the solar panels. However, Nocera's artificial leafs work slightly differently:

First: The nickel-cobalt alloy with the catalyst, can directly break water into hydrogen and oxygen without the need for any apparent electrodes. It's "wireless" electrolysis if you will.

Second: It's all about efficiencies. While photovoltaics could be used to split water, by itself this is not a very efficient process. The secret is in the catalyst which lowers the activation energy of splitting water sufficiently to make photo-catalysis (in this case we are breaking things down) feasible.

The Implications

One of the weaknesses of using photovoltaics is that electricity generation drops to 0 when there is no sun. Artificial leafs could fill this gap by storying part of the energy captured during the day in form of hydrogen and oxygen. In the evening, electricity could be generated again from the stored energy. Nocera has also stated that he hopes these materials are cheap enough so that people in 3rd world countries could easily and cheaply obtain artificial leaves that could be used to power a light source at night.

All in all, very cool research and technology. I will try to keep my eye on this for the future.

Sources:
http://news.cnet.com/8301-11128_3-20047814-54.html
http://www.eurekalert.org/pub_releases/2011-03/acs-dot031811.php

Popular posts from this blog

Focus on Algae - Part I: Bioremediation

After spending the last few blog posts on different aspects of dissimilatory bacteria, I want to switch the focus to a different class of organisms I have been interested in for a long time now. These are the algae. Algae comprise a large diversity of "sea weeds" and an even larger variety of single-celled organisms that mostly are capable of doing photosynthesis. They include the ordinary sea-weed, and make up a portion of the green slime found around the edges and the bottom of a pond. More exotic types of algae can live symbiotically - that is together with another organism in a mutually beneficial way. Lichens are an example of symbiotic relationship between algae and fungi. More information about the evolution and lineage of algae can be found in this wiki article.
Image via Wikipedia
Typically, these organisms are either not mentioned at all or only in conjunction with toxic algal blooms. But lately, algae, of course, have been in the news recently because of the promi…

Sustainable Living: One man's trash...

Since Earth Week is starting tomorrow, I wanted share with you some concrete ways of how individuals like you and me can make an impact on a wider scale. I then also wanted to use this example to challenge everyone to think creatively about the larger context.

So you know how the saying goes: "One man's trash is another one's treasure." Today, I want to talk to you about garbage. Plastic garbage specifically. Plastic is quite a wondrous material. Made from oil by man with just a few additives can turn this polymer into so many different sorts of plastics with so many different properties from thin and flimsy plastic bags, to the carpet on which I am standing, to this plastic bottle from which I am drinking.