Skip to main content

Freely Speaking: What is an Artificial Leaf?

By
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
Labels:

Comments

Post a Comment

Popular posts from this blog

Permaculture: nature is still smarter than us

By
Permaculture In the year 2010, there are many aspects of humans' daily life that would lead us to believe that we have dominated nature. Unlike the thousands of other species that have gone extinct, we have settled and thrived in almost every environment and every continent on this planet, aside from Antarctica. We have eradicated diseases like smallbox and subdued other diseases which previously decimated our populations on a massive scale (see The Black Death in the 1300s and Columbus' “discovery of the Americas in 1492). We have created chemicals that allow us to blast weeds and insects into submission and thereby cultivate thousands of acres of the same species on farmland; an environment that would be impossible in nature. But nature is still smarter than us. A lot smarter. And we still have much to learn from its processes. Permaculture is the idea of mimicking the ways that ecosystems work in the context of essential human activities: house and settlement design, farming...
3 comments
Read more

Journal Club:”An Engineered Microbial Platform for Direct Biofuel Production from Brown Macroalgae”

By
Cover of Science Issue 335. It has been a while since we have done a journal club , and so today I thought I would write about an article I recently read. Adam J. Wargacki, who works in Yasuo Yoshikuni's group, recently published the above titled paper. In light of problems associated with the use of fossil energy sources (cost, scarcity, environmental impact, and geopolitical considerations), the search for new energy sources is starting to become more important. The paper in discussion today proposes that a coupled system consisting of brown macroalgae and engineered bacteria could be used. Of course there are more traditional biofuel feedstock sources such as corn and sugarcane. There a couple of hurdles such as the debate about “food versus fuel” and technical hurdles such as the degradation of lignocellulosic matter that need to be solved. We have previously discussed how microalgaecould get around the difficulties of corn and sugarcane in the production of bioefu...
Post a Comment
Read more

In Other Words: A Life on Our Planet

By
I just watched this documentary together with my son and my wife. Different from David's typical approach of sparse objective commentary, this documentary movie is a personal witness statement that David Attenborough is making describing how our planet has changed in his life time. It's compelling, and urgent but still hopeful.   Please, watch this documentary and share with your friends so they get the message!
3 comments
Read more