Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nano-policing pollution

13.05.2015

Pollutants emitted by factories and car exhausts affect humans who breathe in these harmful gases and also aggravate climate change up in the atmosphere. Being able to detect such emissions is a critically needed measure.

New research by the Nanoparticles by Design Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), in collaboration with the Materials Center Leoben Austria and the Austrian Centre for Electron Microscopy and Nanoanalysis has developed an efficient way to improve methods for detecting polluting emissions using a sensor at the nanoscale. The paper was published in Nanotechnology.


Palladium nanoparticles were deposited on the entire wafer in an evenly distributed fashion, as seen in the background. They also attached on the surface of the copper oxide wire in the same evenly distributed manner, as seen in the foreground. On the upper right is a top view of a single palladium nanoparticle photographed with a transmission electron microscope(TEM) which can only produce black and white images. The nanoparticle is made up of columns consisting of palladium atoms stacked on top of each other. (This image has been modified from the original to provide a better visualization.)

Credit: OIST

The researchers used a copper oxide nanowire decorated with palladium nanoparticles to detect carbon monoxide, a common industrial pollutant. The sensor was tested in conditions similar to ambient air since future devices developed from this method will need to operate in these conditions.

Copper oxide is a semiconductor and scientists use nanowires fabricated from it to search for potential application in the microelectronics industry. But in gas sensing applications, copper oxide was much less widely investigated compared to other metal oxide materials.

A semiconductor can be made to experience dramatic changes in its electrical properties when a small amount of foreign atoms are made to attach to its surface at high temperatures. In this case, the copper oxide nanowire was made part of an electric circuit.

The researchers detected carbon monoxide indirectly, by measuring the change in the resulting circuit's electrical resistance in presence of the gas. They found that copper oxide nanowires decorated with palladium nanoparticles show a significantly greater increase in electrical resistance in the presence of carbon monoxide than the same type of nanowires without the nanoparticles.

The OIST Nanoparticles by Design Unit used a sophisticated technique that allowed them to first sift nanoparticles according to size, then deliver and deposit the palladium nanoparticles onto the surface of the nanowires in an evenly distributed manner. This even dispersion of size selected nanoparticles and the resulting nanoparticles-nanowire interactions are crucial to get an enhanced electrical response.

The OIST nanoparticle deposition system can be tailored to deposit multiple types of nanoparticles at the same time, segregated on distinct areas of the wafer where the nanowire sits. In other words, this system can be engineered to be able to detect multiple kinds of gases. The next step is to detect different gases at the same time by using multiple sensor devices, with each device utilizing a different type of nanoparticle.

Compared to other options being explored in gas sensing which are bulky and difficult to miniaturize, nanowire gas sensors will be cheaper and potentially easier to mass produce.

The main energy cost in operating this kind of a sensor will be the high temperatures necessary to facilitate the chemical reactions for ensuring certain electrical response. In this study 350 degree centigrade was used. However, different nanowire-nanoparticle material configurations are currently being investigated in order to lower the operating temperature of this system.

"I think nanoparticle-decorated nanowires have a huge potential for practical applications as it is possible to incorporate this type of technology into industrial devices," said Stephan Steinhauer, a Japan Society for the Promotion of Science (JSPS) postdoctoral research fellow working under the supervision of Prof. Mukhles Sowwan at the OIST Nanoparticles by Design Unit.

Media Contact

Kaoru Natori
kaoru.natori@oist.jp
81-989-662-389

 @oistedu

http://www.oist.jp/ 

Kaoru Natori | EurekAlert!

More articles from Materials Sciences:

nachricht A new tool for discovering nanoporous materials
23.05.2017 | Ecole Polytechnique Fédérale de Lausanne

nachricht Did you know that packaging is becoming intelligent through flash systems?
23.05.2017 | Heraeus Noblelight GmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>