Easing Atmospheric CO2 Levels Using Nanotubes and Sunlight

[OKIsItJustMe]

http://www.physorg.com/news154007555.html

Easing Atmospheric CO₂ Levels Using Nanotubes and Sunlight

February 16th, 2009 By Laura Mgrdichian in Nanotechnology / Materials

(PhysOrg.com) -- Researchers at The Pennsylvania State University have determined a way to use arrays of nanotubes in a solar-based process to convert carbon dioxide and water into methane and other hydrocarbon fuels. Their method may provide a new way to reduce carbon-dioxide levels in the atmosphere—rising due to our planet's heavy use of fossil fuels—as well as produce alternative fuels.

The rate of carbon dioxide (CO₂) conversion using this method is 20 times higher than that of previously published research. The work is described in the January 27, 2009, online edition of Nano Letters.

"Every 12 days the world consumes about one billion barrels of oil, which represents the release of almost 1 trillion pounds of carbon dioxide into the atmosphere," said the study's lead researcher, Craig Grimes, to PhysOrg.com. "One way of dealing with this problem is by recycling the CO₂ into a high-energy-content fuel, but this makes sense only if a renewable energy source, like solar energy, can be used in the process."

This type of solar-based conversion process only works if a photocatalyst—a material that reacts with light—is used to convert the CO₂ into hydrocarbons. A photocatalyst that utilizes the most solar energy possible is the best option.

…

Grimes and his colleagues used arrays of titania nanotubes. They created the nanotubes using a technique that incorporates nitrogen into the nanotubes' structures, which the researchers initially thought would help increase the conversion rate (this turned out to be true only in a very limited capacity).

…