Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon dots dash toward 'green' recycling role

19.12.2016

Rice scientists, colleagues use doped graphene quantum dots to reduce carbon dioxide to fuel

Graphene quantum dots may offer a simple way to recycle waste carbon dioxide into valuable fuel rather than release it into the atmosphere or bury it underground, according to Rice University scientists.


A single nitrogen-doped graphene quantum dot with zig-zag edges.

Credit: Ajayan Group/Rice University

Nitrogen-doped graphene quantum dots (NGQDs) are an efficient electrocatalyst to make complex hydrocarbons from carbon dioxide, according to the research team led by Rice materials scientist Pulickel Ajayan. Using electrocatalysis, his lab has demonstrated the conversion of the greenhouse gas into small batches of ethylene and ethanol.

The research is detailed this week in Nature Communications.

Though they don't entirely understand the mechanism, the researchers found NGQDs worked nearly as efficiently as copper, which is also being tested as a catalyst to reduce carbon dioxide into liquid fuels and chemicals. And NGQDs keep their catalytic activity for a long time, they reported.

"It is surprising because people have tried all different kinds of catalysts. And there are only a few real choices such as copper," Ajayan said. "I think what we found is fundamentally interesting, because it provides an efficient pathway to screen new types of catalysts to convert carbon dioxide to higher-value products."

Those problems are hardly a secret. Atmospheric carbon dioxide rose above 400 parts per million earlier this year, the highest it's been in at least 800,000 years, as measured through ice-core analysis.

"If we can convert a sizable fraction of the carbon dioxide that is emitted, we could curb the rising levels of atmospheric carbon dioxide levels, which have been linked to climate change," said co-author Paul Kenis of the University of Illinois.

In lab tests, NGQDs proved able to reduce carbon dioxide by up to 90 percent and convert 45 percent into either ethylene or alcohol, comparable to copper electrocatalysts.

Graphene quantum dots are atom-thick sheets of carbon atoms that have been split into particles about a nanometer thick and just a few nanometers wide. The addition of nitrogen atoms to the dots enables varying chemical reactions when an electric current is applied and a feedstock like carbon dioxide is introduced.

"Carbon is typically not a catalyst," Ajayan said. "One of our questions is why this doping is so effective. When nitrogen is inserted into the hexagonal graphitic lattice, there are multiple positions it can take. Each of these positions, depending on where nitrogen sits, should have different catalytic activity. So it's been a puzzle, and though people have written a lot of papers in the last five to 10 years on doped and defective carbon being catalytic, the puzzle is not really solved."

"Our findings suggest that the pyridinic nitrogen (a basic organic compound) sitting at the edge of graphene quantum dots leads the catalytic conversion of carbon dioxide to hydrocarbons," said Rice postdoctoral researcher Jingjie Wu, co-lead author of the paper. "The next task is further increasing nitrogen concentration to help increase the yield of hydrocarbons."

Ajayan noted that while electrocatalysis is effective at lab scales for now, industry relies on scalable thermal catalysis to produce fuels and chemicals. "For that reason, companies probably won't use it any time soon for large-scale production. But electrocatalysis can be easily done in the lab, and we showed it will be useful in the development of new catalysts."

###

Co-lead authors of the paper are Sichao Ma of the University of Illinois at Urbana-Champaign and Kyushu University, Fukuoka, Japan, and Jing Sun of the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences.

Co-authors are Jake Gold, Lingyang Zhu, Aaron Yu and Raymond Luo of the University of Illinois at Urbana-Champaign; Chandra Sekhar Tiwary of Rice; Byoungsu Kim of the University of Illinois at Urbana-Champaign and Kyushu University; Nitin Chopra and Ihab Odeh of SABIC Americas, Inc., Sugar Land, Texas; Robert Vajtai, a senior faculty fellow in materials science and nanoengineering at Rice; Jun Lou, a professor of materials science and nanoengineering at Rice; and Guqiao Ding of the Chinese Academy of Sciences. Kenis is the William H. and Janet G. Lycan Professor and head of chemical and biomolecular engineering at the University of Illinois at Urbana-Champaign with an appointment at Kyushu University.

Ajayan is chair of Rice's Department of Materials Science and NanoEngineering, the Benjamin M. and Mary Greenwood Anderson Professor in Engineering and a professor of chemistry.

SABIC Global Technologies, B.V. supported the research.

Read the abstract at http://www.nature.com/articles/ncomms13869

This news release can be found online at http://news.rice.edu/2016/12/16/carbon-dots-dash-toward-green-recycling-role/

Follow Rice News and Media Relations via Twitter @RiceUNews

Related materials:

Ajayan Research Group: http://ajayan.rice.edu

Rice Department of Materials Science and NanoEngineering: https://msne.rice.edu

Image for download:

http://news.rice.edu/files/2016/12/1219_CARBON-1-WEB-1tenn2c.jpg

Nitrogen-doped graphene quantum dots, like the ones in this transmission electron microscope image, proved adept at catalyzing carbon dioxide into complex hydrocarbons, according to Rice University scientists. (Credit: Ajayan Group/Rice University)

http://news.rice.edu/files/2016/12/1219_CARBON-2-WEB-1zx973u.jpg

A single nitrogen-doped graphene quantum dot with zig-zag edges. (Credit: Ajayan Group/Rice University)

http://news.rice.edu/files/2016/12/1219_CARBON-3-WEB-25470cf.jpg

Nitrogen-doped graphene quantum dots stand out from a substrate in a transmission electron microscope image. The dots are effective electrocatalysts that can reduce carbon dioxide, a greenhouse gas, to valuable hydrocarbons like ethylene and ethanol. (Credit: Ajayan Group/Rice University)

http://news.rice.edu/files/2016/12/1219_CARBON-4-WEB-2czloeq.jpg

An illustration of a nitrogen-doped graphene quantum dot like those being tested at Rice University for use as catalysts to reduce carbon dioxide, a greenhouse gas, into valuable hydrocarbons. (Credit: Ajayan Group/Rice University)

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,910 undergraduates and 2,809 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for happiest students and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

David Ruth
713-348-6327
david@rice.edu

Mike Williams
713-348-6728
mikewilliams@rice.edu

http://news.rice.edu 

David Ruth | EurekAlert!

More articles from Materials Sciences:

nachricht Additive manufacturing reflects fundamental metallurgical principles to create materials
18.01.2019 | University of Sheffield

nachricht Brilliant glow of paint-on semiconductors comes from ornate quantum physics
17.01.2019 | Georgia Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>