Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Finding how carbon nanotubes work as catalysts could lead to cleaner fuels

Graphic by Aleksandr Kalininskiy
Graphic depiction of reactions occurring along a single-walled carbon nanotube converting a nonfluorescent molecule into a fluorescent one. An optical microscope will see fluorescent events as if they were coming from various points around the reaction site -- the upper part of the image shows how this looks through the microscope. But variations in brightness (shown here as different colors) allow researchers to pinpoint the reaction site to within as little as 20 nanometers.
Graphic by Aleksandr Kalininskiy
Graphic depiction of reactions occurring along a single-walled carbon nanotube converting a nonfluorescent molecule into a fluorescent one. An optical microscope will see fluorescent events as if they were coming from various points around the reaction site -- the upper part of the image shows how this looks through the microscope. But variations in brightness (shown here as different colors) allow researchers to pinpoint the reaction site to within as little as 20 nanometers.

Abstract:
Among their many other interesting properties, carbon nanotubes have been found to act as catalysts for some important chemical reactions, including some that could be used to make cleaner fuels. But many unanswered questions remain about how this process works.

Finding how carbon nanotubes work as catalysts could lead to cleaner fuels

Ithaca, NY | Posted on April 16th, 2009

Cornell researchers have answered an important one by pinpointing unique sites where the reactions take place on single-walled nanotubes. But directly observing these sites has been challenging, but now, the researchers have shown that the reactions do not occur all along the tubes, but at the ends of the tubes or at defects along the tubes.

The research by Peng Chen, Cornell assistant professor of chemistry and chemical biology, and his research group was reported April 14 in the online edition of the journal Nano Letters and will appear in a forthcoming print edition.

Carbon nanotubes are microscopic cylinders with walls made of carbon atoms arranged in connected hexagons, somewhat like a rolled up tube of chicken wire. A typical nanotube is a few nanometers (nm) in diameter and several microns long. (A nanometer is one-billionth of a meter, about as long as three atoms in a row. A micron is one-millionth of a meter, or about three times the diameter of a human hair.) Chen's observations have located catalytic reaction sites to within about 20 nm.

Nanotubes act as catalysts when an electric current is passed through them. This enables them to donate electrons to molecules that come in contact with the reaction sites. The reaction is similar to what happens in fuel cells, Chen said, so further research may help in making better fuel cells.

Other researchers at Cornell and elsewhere have shown that carbon nanotubes can be made into transistors. Thus, one long-range goal, Chen added, is to make them into photoelectrochemical cells that would use sunlight directly to make hydrogen.

"We want to use photons to make electrons, then use the electrons in a water-splitting reaction to make hydrogen," he explained, noting that this would help deal with the storage and transportation problems that have hindered the use of solar energy.

Fortuitously, another reaction that carbon nanotubes can catalyze changes a chemical called resazurin into another, resorufin, that is fluorescent. Under a microscope, tiny flashes of light reveal when and where the fluorescent molecules have been created.

Chen's research group trapped an array of nanotubes between transparent conductors in a solution of resazurin and made a "movie" with an exposure every 100 milliseconds over tens of minutes after applying a voltage to start the catalytic reaction. A scattering of bright dots in each frame shows that the reactions are not happening all along the tubes.

Each dot is made up of thousands of photons, and because a light microscope typically cannot resolve features smaller than the wavelength of the light used -- in this case about 400 nm -- they appear scattered. So the researchers used an ingenious mathematical trick, plotting the rise and fall of brightness across each fuzzy dot to pinpoint the center. Think of finding the center aiming point of a shotgun by measuring the distribution of the pellets. Finally they superimposed the centers from all the frames of the movie and repeated the process to refine the locations to within 20 nanometers or less.

"The question now is what are the chemical natures of the reaction sites," Chen said. "Can we see how the electron transfer works?" Now that the sites can be located, he said, it will be possible to use high-resolution scanning tunneling microscopy to observe their atomic structure and relate their structure to electron transfer properties.

The research is supported by a Petroleum Research Foundation grant and by the Cornell Center for Materials Research, which is funded by the National Science Foundation.

####

For more information, please click here

Contacts:
Blaine Friedlander
(607) 254-8093


Cornell Chronicle:
Bill Steele
(607) 255-7164

Copyright © Cornell University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Unraveling the crystal structure of a -70 Celsius superconductor, a world first: Significant advancement in the realization of room-temperature superconductors August 25th, 2016

Stretchy supercapacitors power wearable electronics August 25th, 2016

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Semblant to Present at China Mobile Manufacturing Forum 2016 August 25th, 2016

Chemistry

A new way to display the 3-D structure of molecules: Metal-organic frameworks provide a new platform for solving the structure of hard-to-study samples August 21st, 2016

Researchers watch catalysts at work August 19th, 2016

Pokhara, the second largest city of Nepal, to host its first ever International Meeting on Material Sciences and Engineering August 15th, 2016

'Liquid fingerprinting' technique instantly identifies unknown liquids: Ability to instantly identify unknown liquids in the field could aid first responders, improve plant safety August 4th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

New approach to determining how atoms are arranged in materials August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Possible Futures

Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells August 25th, 2016

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Nanotubes/Buckyballs/Fullerenes

Tunneling nanotubes between neurons enable the spread of Parkinson's disease via lysosomes August 24th, 2016

McMaster researchers resolve a problem that has been holding back a technological revolution August 18th, 2016

'Second skin' protects soldiers from biological and chemical agents August 5th, 2016

Carbon nanotube 'stitches' make stronger, lighter composites: Method to reinforce these materials could help make airplane frames lighter, more damage-resistant August 4th, 2016

Announcements

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

Silicon nanoparticles trained to juggle light: Research findings prove the capabilities of silicon nanoparticles for flexible data processing in optical communication systems August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Environment

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Researchers watch catalysts at work August 19th, 2016

Down to the wire: ONR researchers and new bacteria August 18th, 2016

SLAC, Stanford gadget grabs more solar energy to disinfect water faster: Plopped into water, a tiny device triggers the formation of chemicals that kill microbes in minutes August 15th, 2016

Energy

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Lehigh engineer discovers a high-speed nano-avalanche: New findings published in the Journal of Electrochemical Society about the process involving transformations in glass that occur under intense electrical and thermal conditions could lead the way to more energy-efficient glas August 24th, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic