3 years ago

Oscillations of Cerium Oxidation State Driven by Oxygen Diffusion in Colloidal Nanoceria (CeO 2 − x )

Pavel Maksimchuk, Nikolai Spivak, Yuri Malyukin, Vladyslav Seminko, Vladimir Klochkov

Abstract

The redox performance of CeO2 − x nanocrystals (nanoceria) is always accompanied by the switching of cerium oxidation state between Ce3+ and Ce4+. We monitored Ce3+ → Ce4+ oxidation of nanoceria stimulated by oxidant in aqueous colloidal solutions controlling the luminescence of Ce3+ ions located at different distances from nanoceria surface. The observed Ce3+ luminescence changes indicate that Ce3+ → Ce4+ reaction develops inside nanoceria being triggered by the diffusing oxygen originated from the water splitting on oxidized nanoceria surface. We present the first observation of the pronounced oscillations of Ce3+ luminescence intensity arising from Ce3+ ↔ Ce4+ reversible switching. This threshold effect is to be driven by uptaking and releasing oxygen by nanoceria, when the concentration of oxygen vacancies in nanoceria lattice, oxidant concentration in colloidal solution, and temperature reach certain critical values. So, the ability of nanoceria to uptake and release oxygen depending on the environmental redox conditions really makes it the self-sufficient eternal antioxidant.

Publisher URL: https://link.springer.com/article/10.1186/s11671-017-2339-7

DOI: 10.1186/s11671-017-2339-7

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.