At left: A water molecule interacts with a carbon nanostructure.
_____________________________________________________________________If hydrogen fuel becomes a viable energy source, researchers at North Carolina State University could be part of the solution.

NCSU scientists recently discovered a way to extract hydrogen from water using half the energy required by current methods. They did so by utilizing nanotechnology.

Department of Physics professor Marco Buongiorno-Nardelli; Keith Gubbins, W.H. Clark Distinguished University Professor of Chemical and Biomolecular Engineering; post-doctoral researcher Milen Kostov; and students Erik Santiso and Aaron George made the discovery.

They found that “defective” carbon nanotubes — so miniscule that 1,000 can be stacked to form the thickness of a human hair – make it easier to break up water molecules and extract the hydrogen.

“The discovery could have big implications, namely, lower hydrogen production costs, for industries looking to hydrogen as an alternative fuel,” NCSU said.

The results were published in the Physical Review Letters.

“Normally, when you talk about chemical reactions in carbon nanotubes, you’re imagining that these reactions are happening in perfectly formed nanostructures,” Buongiorno-Nardelli said. “But the reality is that these structures have defects — places where the carbon atom network is broken. And these defects can influence the chemical reaction.”

Carbon nanotubes can facilitate chemical reactions. The NCSU scientists found that naturally occurring defects in the nanotubes “can increase the rate of a chemical reaction, because the atoms that form the defective nanotubes are essentially incomplete, thus making them more reactive,” NCSU said in a statement.

The researchers ran computer models to simulate what would happen if they used the defective nanostructures to break water molecules. They see the nano-application as an alternative to current methods of hydrogen extraction that requires water to be heated to 2,000 degrees Celsius.

“We studied water for many months and ran many different calculations, and we ended up showing that if you want to break a water molecule, you spend a lot less energy if you do it on this defective carbon material than if you do it by simply heating the molecule until it breaks,” Buongiorno-Nardelli said. “You can reduce the energy necessary by a factor of two — you can do it at less than 1,000 degrees.”

The scientists are hopeful that a catalytic process can be developed for hydrogen separation and will explore development of a nanoscale chemical reactor that could lead to a cost-effective as well as energy-efficient means of producing hydrogen.

“We think that nanotechnology can be used to produce more and better energy in an environmentally friendly way,” Buongiorno-Nardelli added. “Our experience with the water molecules so far leads me to believe we’re headed in the right direction.”

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