(Press-News.org) Contact information: Eunhee Song
ehsong@unist.ac.kr
82-522-171-224
Ulsan National Institute of Science and Technology(UNIST)
A noble yet simple way to synthesize new metal-free electrocatalysts for oxygen reduction reaction
Ulsan, S. Korea, Oct 28, 2013 – A Korean research team from Ulsan National Institute of Science and Technology (UNIST), S. Korea, developed a high performance and stable metal-free electrocatalyst for ORR and the research work was published in a science journal, Nanoscale by the Royal Society of Chemistry (RSC). (Title: "Covalent Functionalization Based Heteroatom Doped Graphene Nanosheet as a Metal-Free Electrocatalysts for Oxygen Reduction Reaction")
Limited availability of fossil fuel and increasing energy demands have stimulated intense research on energy conversion and storage systems. Fuel cells have received considerable attention among the many choices of energy storage systems, owing to their remarkable potential energy density and environmental issues.
Electrocatalysts for oxygen reduction are critical components that may dramatically enhance the performance of fuel cells, which are perceived to be the power for future electric vehicles. For more economical fuel cells, engineers need fast and efficient electrocatalysts which split hydrogen gas to make electricity.
The UNIST research team led by Prof. Byeong-Su Kim from the Interdisciplinary School of Green Energy, UNIST, presented a unique design and characterization of new heteroatom-doped graphene nanosheets prepared through the covalent functionalization of various small organic molecules with a subsequent thermal treatment. This work was proposed and carried out by undergraduate student Minju Park from the Interdisciplinary School of Green Energy, UNIST.
There are many available methods to prepare nitrogen-doped (N-doped) graphene. These approaches successfully introduce nitrogen atoms within the graphene framework. However, many of them require toxic gas precursors, and are unable to control the degree of doping and type of nitrogen functionality.
Herein the UNIST Research team presented a simple approach for chemical functionalization toward heteroatom-dope graphene nanosheets with small organic molecules for use as electrocatalysts for the oxygen reduction reaction.
Here is how the material has been prepared:
Graphite oxide powder was prepared from graphite powder with oxidation and exfoliated to give a brown dispersion of graphene oxide (GO) under ultra sonication. Graphene oxide nanosheets have various functional groups on the edge such as carboxylic (-COOH), hydroxyl (-OH), and epoxy (-C-O-C).
When the GO suspension reacted with amines in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), a water soluble carbodiimide was usually obtained as the hydrochloride, carboxylic group in GO reacted with amine and formed an amide group. The research team defined it as 'NGOn', which was chemically functionalized graphene oxide. NGOn suspensions were annealed at 800 ℃ for 1h under an argon atmosphere with tube furnace, and nitrogen was doped into the graphene oxide nanosheets with removing oxygen named 'NRGOn'.
Further the UNIST research team demonstrated how the electrochemical performance can be improved by varying the degree and configurations of the nitrogen dopant. Further, they extended the approach toward the introduction of other heteroatoms, such as boron and sulfur, into the graphene nanosheet.
"Nitrogen-doped graphene nanosheets showed superior stability compared to commercial Pt/C catalysts. This approach has also been successfully extended to other heteroatoms such as boron and sulfur on the graphene nanosheets," said Minju Park.
"We envision this study will offer opportunities and insights for further development of hybrid electrocatalysts," said Prof. Kim, presenting future research possibilities.
INFORMATION:
This research work was supported by the National Research Foundation of Korea (NRF) grant.
A noble yet simple way to synthesize new metal-free electrocatalysts for oxygen reduction reaction
2013-10-28
ELSE PRESS RELEASES FROM THIS DATE:
How problems with an Alzheimer's protein can jam up traffic in the brain
2013-10-28
How problems with an Alzheimer's protein can jam up traffic in the brain
Study shows how the wrong levels of a protein linked with Alzheimer's disease can lead to dangerous blockages in brain cells
BUFFALO, N.Y. — Scientists have known for some time that a protein ...
Social science graduates more likely to be in work than science or arts graduates, report says
2013-10-28
Social science graduates more likely to be in work than science or arts graduates, report says
Social science graduates are more likely to be in employment after their first degree than graduates in other areas such as science and the arts, and a higher proportion ...
Minimally invasive surgery for paraesophageal hernia is 'revolutionary' -- but experts still differ on
2013-10-28
Minimally invasive surgery for paraesophageal hernia is 'revolutionary' -- but experts still differ on
'Current controversies' in laparascopic paraesophageal hernia repair are highlighted in Surgical Laparoscopy, Endoscopy & Percutaneous Techniques
Philadelphia, ...
Many bushfires in New South Wales, Australia
2013-10-28
Many bushfires in New South Wales, Australia
NASA's Terra satellite detected dozens of bushfires continued raging in the Australian state of New South Wales, outside of Sydney. Sydney is the state capital and the most populated city in Australia.
According to ...
Extra-Tropical Storm Lekima weakens in Northern Pacific
2013-10-28
Extra-Tropical Storm Lekima weakens in Northern Pacific
Once a typhoon now an extra-tropical cyclone in the far northern Pacific Ocean, Lekima is weakening over cool waters. NASA's Aqua satellite captured the last image of Lekima as a typhoon before it weakened.
On ...
The Chemistry of Fear: A new video from the American Chemical Society
2013-10-28
The Chemistry of Fear: A new video from the American Chemical Society
With Halloween just a few days away, millions are flocking to horror films and haunted houses for their annual dose of terror. The latest video from the American Chemical Society's (ACS) ...
Poor motor performance linked to poor academic skills in the first school years
2013-10-28
Poor motor performance linked to poor academic skills in the first school years
Children with poor motor performance at the school entry were found to have poorer reading and arithmetic skills than their better performing peers during the first three years of school. However, ...
Crying wolf: Who benefits and when?
2013-10-28
Crying wolf: Who benefits and when?
BLOOMINGTON, Ind. -- A crisis at work can bring out the best in colleagues, often inspiring more cooperation and self-sacrifice. A new study from Indiana University and the University of Guelphhas found that the benefits are not shared ...
New imaging research shows increased iron in the brain in earliest stages of MS
2013-10-28
New imaging research shows increased iron in the brain in earliest stages of MS
VIDEO:
As Western University scientist Ravi Menon, Ph.D., explains, it's ...
Discovery could lead to anti-clotting drugs with less risk of bleeding
2013-10-28
Discovery could lead to anti-clotting drugs with less risk of bleeding
Researchers at the University of Illinois at Chicago have discovered a molecular switch that causes small, beneficial clots that stop bleeding to enlarge further during wound healing. ...