Researchers inadvertently boost surface area of nickel nanoparticles for catalysis

November 28, 2017 by Matt Shipman
During deposition of a silica shell onto Ni nanoparticles, they are etched, oxidized, and embedded in the silica, which stabilizes the structure during oxidation and reduction. Credit: Brian Lynch. Reproduced by permission of The Royal Society of Chemistry.

Researchers from North Carolina State University and the Air Force Research Laboratory have discovered that a technique designed to coat nickel nanoparticles with silica shells actually fragments the material – creating a small core of oxidized nickel surrounded by smaller satellites embedded in a silica shell. The surprising result may prove useful by increasing the surface area of nickel available for catalyzing chemical reactions.

"Nickel is noteworthy for its widespread applications in catalysis," says Joe Tracy, an associate professor of materials science and engineering at NC State and corresponding author of a paper on the work. "One reason you'd want to coat nanoparticles in porous silica is to embed them in a neutral substrate to maintain their efficiency as catalysts in chemical reactions. So the fact that this process could increase their at the same time could prove to be beneficial."

The researchers employed a widely used approach called reverse microemulsion, or reverse micelle, to apply a to nickel nanoparticles that were approximately 27 nanometers (nm) in diameter. But they found that the technique results in an oxidized nickel core that was 7 nm in diameter, surrounded by oxidized nickel satellites only 2 nm in diameter – all enclosed in a silica shell that was 30 nm in diameter.

"At first we thought we'd made a mistake, but we were able to reproduce the result over and over again," says Brian Lynch, a Ph.D. student at NC State and lead author of a paper on the work.

"When oxidized and reduced at high temperatures, we found that the core-and-satellite nickel nanoparticles did not significantly change size or shape, suggesting that they would function well in the environments needed to catalyze ," Tracy says.

"This was an unexpected discovery, but we're happy with how it turned out."

The paper, "Synthesis and Chemical Transformation of Ni Nanoparticles Embedded in Silica," is published in the journal Nanoscale.

Explore further: Size matters when reducing NiO nanoparticles

More information: Brian B. Lynch et al. Synthesis and chemical transformation of Ni nanoparticles embedded in silica, Nanoscale (2017). DOI: 10.1039/C7NR06379B

Related Stories

Size matters when reducing NiO nanoparticles

November 27, 2012

(Phys.org)—New research finds that size plays a major role in how nanoscale nickel oxide (NiO) shells behave when being reduced to solid nickel nanoparticles.

Nickel-78 confirmed to be doubly magic

November 8, 2017

(Phys.org)—Two teams of researchers working independently of one another and using wildly different approaches have confirmed nickel-78 to be doubly magic. In the first effort, an international team led by Louis Olivier ...

Recommended for you

Splitting water: Nanoscale imaging yields key insights

July 18, 2018

In the quest to realize artificial photosynthesis to convert sunlight, water, and carbon dioxide into fuel—just as plants do—researchers need to not only identify materials to efficiently perform photoelectrochemical ...

Single-celled architects inspire new nanotechnology

July 16, 2018

Diatoms are tiny, unicellular creatures, inhabiting oceans, lakes, rivers, and soils. Through their respiration, they produce close to a quarter of the oxygen on earth, nearly as much as the world's tropical forests. In addition ...

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.