Journal article
High-surface-area corundum nanoparticles by resistive hotspot-induced phase transformation
Nature communications, Vol.13(1), pp.5027-5027
08/26/2022
DOI: 10.1038/s41467-022-32622-4
PMCID: PMC9418197
PMID: 36028480
Abstract
High-surface-area alpha-Al2O3 nanoparticles are used in high-strength ceramics and stable catalyst supports. The production of alpha-Al2O3 by phase transformation from gamma-Al2O3 is hampered by a high activation energy barrier, which usually requires extended high-temperature annealing (similar to 1500 K, > 10 h) and suffers from aggregation. Here, we report the synthesis of dehydrated alpha-Al2O3 nanoparticles (phase purity similar to 100%, particle size similar to 23 nm, surface area similar to 65 m(2) g(-1)) by a pulsed direct current Joule heating of gamma-Al2O3. The phase transformation is completed at a reduced bulk temperature and duration (similar to 573 K, < 1 s) via an intermediate delta'-Al2O3 phase. Numerical simulations reveal the resistive hotspot-induced local heating in the pulsed current process enables the rapid transformation. Theoretical calculations show the topotactic transition (from gamma- to delta'- to alpha-Al2O3) is driven by their surface energy differences. The alpha-Al2O3 nanoparticles are sintered to nanograined ceramics with hardness superior to commercial alumina and approaching that of sapphire.
Details
- Title: Subtitle
- High-surface-area corundum nanoparticles by resistive hotspot-induced phase transformation
- Creators
- Bing Deng - Rice UniversityPaul A. Advincula - Rice UniversityDuy Xuan Luong - Rice UniversityJingan Zhou - Rice UniversityBoyu Zhang - Rice UniversityZhe Wang - Rice UniversityEmily A. McHugh - Rice UniversityJinhang Chen - Rice UniversityRobert A. Carter - Rice UniversityCarter Kittrell - Rice UniversityJun Lou - Rice UniversityYuji Zhao - Rice UniversityBoris I. Yakobson - Rice UniversityYufeng Zhao - Rice UniversityJames M. Tour - Rice University
- Resource Type
- Journal article
- Publication Details
- Nature communications, Vol.13(1), pp.5027-5027
- Publisher
- NATURE PORTFOLIO
- DOI
- 10.1038/s41467-022-32622-4
- PMID
- 36028480
- PMCID
- PMC9418197
- ISSN
- 2041-1723
- eISSN
- 2041-1723
- Number of pages
- 12
- Grant note
- FA9550-19-1-0296 / Air Force Office of Scientific Research; United States Department of Defense; Air Force Office of Scientific Research (AFOSR) N00014-18-1-2182 / Office of Naval Research W912HZ-21-2-0050 / U.S. Army Corps of Engineers, ERDC
- Language
- English
- Date published
- 08/26/2022
- Academic Unit
- Chemical and Biochemical Engineering
- Record Identifier
- 9984696791002771
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