Nav: Home

Determining the activity of noble-metal-free catalyst particles

October 04, 2019

Chemists have developed a new method with which they can characterise individual noble-metal-free nanoparticle catalysts. The particles could be a cheap alternative to precious metal catalysts for obtaining hydrogen from water by means of electrolysis. "In order to develop effective nanoparticles, we need to understand how the structure and activity of individual particles or small particle groups are related to each other," says Professor Wolfgang Schuhmann of the Center for Electrochemistry at Ruhr-Universität Bochum. He describes a new measurement method for this purpose together with the researchers Tsvetan Tarnev and Dr. Harshitha Barike Ayappa from Bochum and Professor Corina Andronescu from the University of Duisburg-Essen and other colleagues in the journal Angewandte Chemie of 1 October 2019.

So far, there are few techniques available to measure the catalytic activity of individual or a few nanoparticles. "The currents that have to be measured are extremely small, and one has to find single or few nanoparticles in order to measure them reproducibly," explains Schuhmann. The research team, which cooperates within the University Alliance Ruhr, showed that such analyses are also possible with high throughput - namely with scanning electrochemical cell microscopy.

Development of a new reference system

Until now, the method had not been used for this purpose because the nanoparticles had to be tested under demanding chemical conditions and thus large measurement inaccuracies occurred. This made a reliable interpretation of the results impossible. In their current work, the researchers developed a new reference system for scanning electrochemical cell microscopy. By cleverly using a stable internal standard, they eliminated the measurement inaccuracies and enabled long-lasting measurements under the given conditions with high throughput.

Analysis of self-made nanoparticles

The researchers produced carbon particles with nitrogen and cobalt inclusions on glassy carbon, the particles being present on the surface either individually or in groups of a few particles. In a single experiment, they were able to use scanning electrochemical cell microscopy to determine the electrochemical activity of all these individual particles or particle groups.

The particles catalysed the so-called oxygen evolution reaction. The electrolysis of water produces hydrogen and oxygen - the limiting step in this process is currently the partial reaction in which oxygen is evolved; more efficient catalysts for this partial reaction would facilitate the production of hydrogen.
-end-
University Alliance Ruhr

Since 2007, the three Ruhr region universities have been engaged in close strategic cooperation under the umbrella of the University Alliance Ruhr (UA Ruhr). By pooling their strengths, the partner institutions are systematically expanding their output. There are now over 100 cooperations in the fields of research, teaching and administration, all built on the principle of being "better together". With over 120,000 students and almost 1,300 professors, the UA Ruhr is one of the largest and best-performing hubs for science and technology in Germany.

Ruhr-University Bochum

Related Nanoparticles Articles:

Study models new method to accelerate nanoparticles
In a new study, researchers at the University of Illinois and the Missouri University of Science and Technology modeled a method to manipulate nanoparticles as an alternative mode of propulsion for tiny spacecraft that require very small levels of thrust.
Actively swimming gold nanoparticles
Bacteria can actively move towards a nutrient source -- a phenomenon known as chemotaxis -- and they can move collectively in a process known as swarming.
Nanoparticles take a fantastic, magnetic voyage
MIT engineers have designed tiny robots that can help drug-delivery nanoparticles push their way out of the bloodstream and into a tumor or another disease site.
Quantum optical cooling of nanoparticles
One important requirement to see quantum effects is to remove all thermal energy from the particle motion, i.e. to cool it as close as possible to absolute zero temperature.
Nanoparticles help realize 'spintronic' devices
For the first time researchers have demonstrated a new way to perform functions essential to future computation three orders of magnitude faster than current commercial devices.
Directed evolution builds nanoparticles
Directed evolution is a powerful technique for engineering proteins. EPFL scientists now show that it can also be used to engineer synthetic nanoparticles as optical biosensors, which are used widely in biology, drug development, and even medical diagnostics such as real-time monitoring of glucose.
What happens to magnetic nanoparticles once in cells?
Although magnetic nanoparticles are being used more and more in cell imaging and tissue bioengineering, what happens to them within stem cells in the long term remained undocumented.
Watching nanoparticles
Stanford researchers retooled an electron microscope to work with visible light and gas flow, making it possible to watch a photochemical reaction as it swept across a nanoparticle the size of a single cold virus.
Nanoparticles to treat snakebites
Venomous snakebites affect 2.5 million people, and annually cause more than 100,000 deaths and leave 400,000 individuals with permanent physical and psychological trauma each year.
Nanoparticles in our environment may have more harmful effects than we think
Researchers warn that a combination of nanoparticles and contaminants may form a cocktail that is harmful to our cells.
More Nanoparticles News and Nanoparticles Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.