Welcome to DU!
The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards.
Join the community:
Create a free account
Support DU (and get rid of ads!):
Become a Star Member
Latest Breaking News
General Discussion
The DU Lounge
All Forums
Issue Forums
Culture Forums
Alliance Forums
Region Forums
Support Forums
Help & Search
A breath of fresh air: Three-layer nanoparticle catalysts improve zinc-air batteries
http://www.research.a-star.edu.sg/research/7638/a-breath-of-fresh-air[font face=Serif][font size=5]A breath of fresh air[/font]
[font size=4]Three-layer nanoparticle catalysts improve zinc-air batteries[/font]
Published online Jan 4, 2017
[font size=3]Nanoparticles containing three different layers of material can help to boost the performance of a zinc-air battery, A*STAR researchers have found.
Zinc-air batteries are cheap, have a high energy density, and last for a very long time. Their use of a water-based electrolyte makes them safer than other batteries, so they’re often found in medical applications, such as hearing aids and heart monitoring devices.
…
Yun Zong and Zhaolin Liu of the A*STAR Institute of Materials Research and Engineering and colleagues have developed a nanoparticle catalyst that could fit the bill. The particles are 20–50 nanometers across, with a cobalt core encased by an inner shell of cobalt oxide, which is surrounded by an outer shell of pyrolyzed polydopamine (PPD), a form of carbon ‘dotted’ with nitrogen atoms. These nanoparticles are coated on a porous carbon support that acts as an electrode. Their structure helps to prevent them from leaching cobalt or clumping together, and the protective outer shell also makes the nanoparticles more durable.
These three-layer nanoparticles efficiently transformed oxygen to hydroxide in a single step. The team suggests that nitrogen atoms in the PPD shell help to attract and make oxygen atoms more reactive on their way to catalytically active sites in the cobalt oxide and PPD. Meanwhile, the cobalt core and PPD shell help electrons to flow efficiently to the oxygen atoms. In contrast, similar particles containing only cobalt and cobalt oxide, or PPD alone, transformed oxygen in a two-step process that produced hydroperoxide, an undesirable and corrosive intermediate.
…[/font][/font]
http://dx.doi.org/10.1002/smll.201503694[font size=4]Three-layer nanoparticle catalysts improve zinc-air batteries[/font]
Published online Jan 4, 2017
[font size=3]Nanoparticles containing three different layers of material can help to boost the performance of a zinc-air battery, A*STAR researchers have found.
Zinc-air batteries are cheap, have a high energy density, and last for a very long time. Their use of a water-based electrolyte makes them safer than other batteries, so they’re often found in medical applications, such as hearing aids and heart monitoring devices.
…
Yun Zong and Zhaolin Liu of the A*STAR Institute of Materials Research and Engineering and colleagues have developed a nanoparticle catalyst that could fit the bill. The particles are 20–50 nanometers across, with a cobalt core encased by an inner shell of cobalt oxide, which is surrounded by an outer shell of pyrolyzed polydopamine (PPD), a form of carbon ‘dotted’ with nitrogen atoms. These nanoparticles are coated on a porous carbon support that acts as an electrode. Their structure helps to prevent them from leaching cobalt or clumping together, and the protective outer shell also makes the nanoparticles more durable.
These three-layer nanoparticles efficiently transformed oxygen to hydroxide in a single step. The team suggests that nitrogen atoms in the PPD shell help to attract and make oxygen atoms more reactive on their way to catalytically active sites in the cobalt oxide and PPD. Meanwhile, the cobalt core and PPD shell help electrons to flow efficiently to the oxygen atoms. In contrast, similar particles containing only cobalt and cobalt oxide, or PPD alone, transformed oxygen in a two-step process that produced hydroperoxide, an undesirable and corrosive intermediate.
…[/font][/font]
