Bench Press

CO₂ + 2 H₂O + light –> (CH₂O)_n + H₂O + O₂

The equation above was the first thing I ever learned about photosynthesis. A simple equation that stated that the input of water, carbon dioxide, and light would allow a plant to produce sugar, water, and oxygen. The equation is just a simple overview of the impressive chain of events that take place within each cell of a plant undergoing photosynthesis. While scientists have studied and admired photosynthesis in great detail; producing a cost-effective artificial system for harnessing light for energy has proven to be a difficult proposition.

Today, much of the research being done focuses on finding ways to improve efficiency of solar cells thereby making them more cost effective. Some research is even being done to produce artificial “trees” that contain solar cells in the leaves as well as piezoelectric elements to harness kinetic energy from the wind and rain. While all these different approaches are promising and are obviously photosynthesis inspired none of them truly imitate the basic chemical reaction that is the crux of photosynthesis. That’s why I was really impressed when I read about researchers, at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, who’ve discovered nanocrystals of cobalt oxide are capable of splitting water with only the application of visible light.

An excerpt from Physorg.com’s article:

Green plants perform the photooxidation of water molecules within a complex of proteins called Photosystem II, in which manganese-containing enzymes serve as the catalyst. Manganese-based organometallic complexes modeled off Photosystem II have shown some promise as photocatalysts for water oxidation but some suffer from being water insoluble and none are very robust. In looking for purely inorganic catalysts that would dissolve in water and would be far more robust than biomimetic materials, Frei and Jiao turned to cobalt oxide, a highly abundant material that is an an important industrial catalyst. When Frei and Jiao tested micron-sized particles of cobalt oxide, they found the particles were inefficient and not nearly fast enough to serve as photocatalysts. However, when they nano-sized the particles it was another story.

“The yield for clusters of cobalt oxide (Co₃O₄) nano-sized crystals was about 1,600 times higher than for micron-sized particles,” said Frei, “and the turnover frequency (speed) was about 1,140 oxygen molecules per second per cluster, which is commensurate with solar flux at ground level (approximately 1,000 Watts per square meter).”

Frei and Jiao hope to tie this breakthrough into a liquid fuel producing system that’s renewable and scrubs the atmosphere of CO₂ in the process. With their work on cobalt oxide they’ve made an important first step in producing a viable artificial photosynthetic system. I sure hope nature’s ok with us taking a page from her playbook.

(Image Credit – Simple Photosynthesis , Image Credit – Aritifical photosynthesis concept , Complete Physorg.com article)

*edited the photosynthesis formula meant to use the general one, but instead I used some wack combination of the two.

Been on a blogging hiatus thanks to various lab issues that have cropped up over the past month. It’s amazing how much stuff one has to do to move a lab that hasn’t moved in 12 years… Anyway, here’s a few science tidbits that caught my eye over the past few weeks.

• Developing more efficient green technologies ftw.
• DARPA awards $1.95 million contract for developing “a ‘fieldable’ in-theather, culture-manufacturing system” for “blood pharming”.
• Having worked on drug discovery for HIV and now working on gene therapy vectors, this story in the WSJ about a bone marrow transplant curing a 42-year old of AIDS is remarkable and heartening.
• A troubling legal ruling about liability for generic drugs.