Carbonized TiO2 nanotubes with semimetallic properties increase the efficiency of methanol fuel cells

September 8, 2009

(PhysOrg.com) -- Mention of nanotubes usually means carbon nanotubes. But not all tiny tubes are made of carbon. For example, layers made of nanoscopic titanium dioxide have proven to be useful materials for biotechnology, catalytic converters, and solar cell technology. Although the semiconducting properties of these nanotubes are critical for many of these applications, their limited conductivity represents a hindrance for other areas of application.

A team at the University of Erlangen-Nürnberg and the University of Turku in Finland has now found an easy way to breathe some metal-like conductivity into the nanotubes without changing their structure. Through carbonization, the can be converted into a carbon-containing titanium oxycarbide compound. As the researchers led by Patrik Schmuki report in the journal , this novel material could drastically increase the efficiency of fuel cells.

In order to carbonize titanium dioxide nanotubes, the researchers treated them with acetylene at 850 °C. This forms a carbon-rich compound with semimetallic properties, which is also significantly harder than before carbonization. “This is not about simply doping titanium dioxide with atoms,” clarifies Schmuki. “Although the ordered tube structures remain almost completely unchanged, a new chemical compound is formed. This titanium oxycarbide can be interpreted as a solid mixture of titanium carbide and various titanium oxides.” Its high electrical conductivity and favorable electrochemical characteristics make this new material an interesting new electrode material.

Its use in methanol fuel cells seems particularly attractive. These days, methanol oxidation is usually carried out at catalytic electrodes with a carbon support and a platinum or ruthenium catalyst. “Titanium dioxide nanotubes have been under consideration as an alternative to the carbon support for a number of years,” says Schmuki. “But our new conducting oxycarbide beats these by a mile: Supports made of the oxycarbide increase the activity of the catalyst for the methanol oxidation by 700 %.”

More information: Patrik Schmuki, Semimetallic TiO2 Nanotubes, Angewandte Chemie International Edition 2009, 48, No. 39, 7236-7239, doi: 10.1002/anie.200902207

Provided by Wiley (news : web)

Explore further: Nano World: Methanol fuel cell thru nano

Related Stories

Hydrogen generation without the carbon footprint

July 15, 2008

A greener, less expensive method to produce hydrogen for fuel may eventually be possible with the help of water, solar energy and nanotube diodes that use the entire spectrum of the sun's energy, according to Penn State researchers. ...

'Metal-Decorated' Nanotubes Hold Promise for Fuel Cells

May 4, 2005

New quantum calculations and computer models show that carbon nanotubes "decorated" with titanium or other transition metals can latch on to hydrogen molecules in numbers more than adequate for efficient hydrogen storage, ...

Sunlight turns carbon dioxide to methane

March 5, 2009

Dual catalysts may be the key to efficiently turning carbon dioxide and water vapor into methane and other hydrocarbons using titania nanotubes and solar power, according to Penn State researchers.

Bone-growing nanomaterial could improve orthopaedic implants

September 17, 2007

For orthopaedic implants to be successful, bone must meld to the metal that these artificial hips, knees and shoulders are made of. A team of Brown University engineers, led by Thomas Webster, has discovered a new material ...

Recommended for you

Particles self-assemble into Archimedean tilings

December 8, 2016

(Phys.org)—For the first time, researchers have simulated particles that can spontaneously self-assemble into networks that form geometrical arrangements called Archimedean tilings. The key to realizing these structures ...

Nano-calligraphy on graphene

December 8, 2016

Scientists at The University of Manchester and Karlsruhe Institute of Technology have demonstrated a method to chemically modify small regions of graphene with high precision, leading to extreme miniaturisation of chemical ...

ANU invention to inspire new night-vision specs

December 7, 2016

Scientists at The Australian National University (ANU) have designed a nano crystal around 500 times smaller than a human hair that turns darkness into visible light and can be used to create light-weight night-vision glasses.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.