Enhanced oxidation of nanoparticles through strain-mediated ionic transport

Andrew Pratt, Leonardo Lari, Ondrej Hovorka, Amish Shah, Charles Woffinden, Steve Tear, Chris Binns, Roland Kröger

Research output: Contribution to journalArticlepeer-review


Geometry and confinement effects at the nanoscale can result in substantial modifications to a material's properties with significant consequences in terms of chemical reactivity, biocompatibility and toxicity. Although benefiting applications across a diverse array of environmental and technological settings, the long-term effects of these changes, for example in the reaction of metallic nanoparticles under atmospheric conditions, are not well understood. Here, we use the unprecedented resolution attainable with aberration-corrected scanning transmission electron microscopy to study the oxidation of cuboid Fe nanoparticles. Performing strain analysis at the atomic level, we reveal that strain gradients induced in the confined oxide shell by the nanoparticle geometry enhance the transport of diffusing species, ultimately driving oxide domain formation and the shape evolution of the particle. We conjecture that such a strain-gradient-enhanced mass transport mechanism may prove essential for understanding the reaction of nanoparticles with gases in general, and for providing deeper insight into ionic conductivity in strained nanostructures.
Original languageEnglish
Article numbern/a
Pages (from-to)26-30
Number of pages5
JournalNature Materials
Issue number1
Early online date3 Nov 2013
Publication statusPublished - Jan 2014

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