Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscale islands dot light-driven catalyst

05.10.2017

Rice University scientists develop method to make multifunctional plasmonic nanostructures

Individual nanoscale nuggets of gold, copper, aluminum, silver and other metals that capture light's energy and put it to work are being employed by Rice University scientists who have discovered a way to build multifunctional nanoscale structures.


Researchers at Rice University and the University of Cambridge made and characterized aluminum nanostructures decorated with 'islands' of various transition metals (above, palladium and ruthenium). The versatile plasmonic allows for customizable surface chemistry and reactivity in one-material nanostructures.

Credit: Rowan Leary/University of Cambridge

Usage Restrictions: For news reporting purposes only.

The structures have an aluminum core and are dotted with even smaller metallic islands. The materials all sustain localized surface plasmon resonances, collective oscillations of the electrons inside the nanostructure that activate when light hits the particle.

These nanoscale oscillations in electron density can power chemical reactions and even power reaction-promoting catalysts.

The technique developed in the labs of Rice materials scientists Emilie Ringe and Naomi Halas uses aluminum nanocrystals as a base for size-tunable transition metal islands that enable localized surface plasmon resonances. Aluminum is an effective plasmonic material, but adding smaller catalytic particles from three columns of the periodic table enhances the structure's ability to promote chemical reactions driven by light's energy, as shown in a previous collaboration between the Halas and Ringe groups.

The technique allows for customizable surface chemistry and reactivity in one material, the researchers said. It could be useful for photocatalysis, surface-enhanced spectroscopy and quantum plasmonics, the study of the quantum properties of light and how they interact with nanoparticles.

The research appears in the American Chemical Society journal ACS Nano.

The researchers said their general polyol technique can be used to combine multiple materials in a simple, controllable process.

Rice graduate student and lead author Dayne Swearer and his colleagues used a two-step synthetic method that began with the reduction of an aluminum precursor to purified aluminum particles between 50 and 150 nanometers wide. They suspended the particles in ethylene glycol, added a metal salt precursor and boiled the solution to reduce the salts that eventually nucleated and grew into nano-islands that decorated the surface of the original aluminum nanocrystals.

The researchers found using an electron microscope that a 2- to 4-nanometer native aluminum oxide layer separated the aluminum nanocrystal and catalytic nano-islands. Additionally, in collaboration with Rowan Leary and Paul Midgley, material scientists at Cambridge University, the team was able to use electron tomography to identify the size and location of more than 500 individual ruthenium nano-islands on a single aluminum nanocrystal.

"The naturally occurring nanoscale geometry of these new materials is really exciting," Swearer said. "Because a thin layer of aluminum oxide separates the two materials, we can independently tune their properties to suit our needs in future applications."

The lab used the method to decorate aluminum nanocrystals with iron, cobalt, nickel, ruthenium rhodium, platinum, palladium and iridium. The islands were as small as 2 nanometers wide and as large as 15 nanometers.

Custom-designed devices that couple aluminum and plasmonic islands will make sought-after reactions easier to trigger, Ringe said.

In 2016, the team showed that aluminum nanocrystals decorated with palladium islands, made using a different method, could be used for selective hydrogenations when exposed to light that were not possible when simply heated in the dark. "We hope that with this new, expansive library of similar nanomaterials, many new types of previously inaccessible chemical reactions will become possible," Swearer said.

The islands' small size makes them better at absorbing light than larger nanoparticles and also makes them better at producing hot electrons and injecting them into target molecules for catalysis, he said.

"The synthesis could be used to make even more elaborate combinations of metals and semiconductors from the periodic table," Swearer said. "Each new material combination has the potential to be explored for several applications."

###

Co-authors of the paper are Rice researchers Ryan Newell and Sadegh Yazdi, graduate students Hossein Robatjazi, Yue Zhang and David Renard, and Peter Nordlander, a professor of physics and astronomy, of electrical and computer engineering and of materials science and nanoengineering. Leary is a research fellow and Midgley is a professor of materials science at the University of Cambridge. Swearer is co-advised by Ringe and Halas.

Ringe is an assistant professor of materials science and nanoengineering and of chemistry. Halas is the Stanley C. Moore Professor of Electrical and Computer Engineering, a professor of chemistry, of bioengineering, of physics and astronomy and of materials science and nanoengineering and director of the Laboratory for Nanophotonics and of the Smalley-Curl Institute.

The research was supported by the National Science Foundation, the Air Force Office of Scientific Research's Multidisciplinary University Research Initiative, the Army Research Office, the Defense Threat Reduction Agency, the Welch Foundation and the American Chemical Society Petroleum Research Fund.

Read the abstract at http://pubs.acs.org/doi/10.1021/acsnano.7b04960

This news release can be found online at http://news.rice.edu/2017/10/04/nanoscale-islands-dot-light-driven-catalyst/

Follow Rice News and Media Relations via Twitter @RiceUNews

Video:

1008_ALUMINUM%20movie

https://youtu.be/g9nL-PbXAeU

An animation shows the position of hundreds of ruthenium nano-islands on a single aluminum nanocrystal. Rice University scientists combined aluminum nanoparticles and smaller metal particles to create versatile plasmonic nanostructures. The technique allows for customizable surface chemistry and reactivity in one material. (Credit: Rice University/University of Cambridge)

Related materials:

Rice's "antenna-reactor" catalysts offer best of both worlds: http://news.rice.edu/2016/07/18/rices-antenna-reactor-catalysts-offer-best-of-both-worlds-2/

Ringe Group: http://ringegroup.rice.edu

Halas Research Group: http://halas.rice.edu

Electron Microscopy Group (Midgley): http://www-hrem.msm.cam.ac.uk/hrem/index.shtml

Laboratory for Nanophotonics: http://lanp.blogs.rice.edu

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

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 3,879 undergraduates and 2,861 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 quality of life and for lots of race/class interaction and No. 2 for happiest students 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.

Media Contact

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

 @RiceUNews

http://news.rice.edu 

David Ruth | EurekAlert!

More articles from Materials Sciences:

nachricht Borophene shines alone as 2-D plasmonic material
21.11.2017 | Rice University

nachricht Quantum dots amplify light with electrical pumping
21.11.2017 | DOE/Los Alamos National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>