Abstract
Atom probe tomography (APT) analysis of chemically pure nanofilms of zerovalent iron (Fe(0), or ZVI) and their thermal oxide nano-overlayers reveals the presence of dendritic iron oxide features that extend from the oxide nano-overlayer surface into the ZVI bulk. The dendrites are observed by APT to be in the 5 nm × 10 nm size range and form quickly under natural atmospheric conditions. Their growth into the ZVI layer is, within the limit of our three month long study, self-limiting (i.e., their initial growth appears to quickly discontinue). The atomistic views presented here shed first light on the atmospheric corrosion process of Fe(0)-bearing engineered nanostructures and their surfaces in the limit of low bulk impurities. Possible roles of the newly identified oxidized iron dendrites are also discussed in the context of passivation processes limiting technological applications of Fe(0).
| Original language | English (US) |
|---|---|
| Pages (from-to) | 28225-28232 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 49 |
| DOIs | |
| State | Published - Dec 13 2018 |
Funding
This work was supported by the US National Science Foundation (NSF). F.M.G. gratefully acknowledges NSF award number CHE-1464916 and support from a Friedrich Wilhelm Bessel Prize from the Alexander von Humboldt Foundation. The XPS work was performed in the Keck-II facility of NUANCE Center at Northwestern University. The NUANCE Center is supported by the International Institute for Nanotechnology, MRSEC (NSF DMR-1121262), the Keck Foundation, the State of Illinois, and Northwestern University. This work made use of the EPIC facility (NUANCE Center-Northwestern University), which has received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); and the State of Illinois, through the IIN. Atom probe tomography was performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph at NUCAPT was purchased and upgraded with grants from the NSF-MRI (DMR-0420532) and ONR-DURIP (N00014-0400798, N00014-0610539, N00014-0910781, N00014-1712870) programs. NUCAPT received support from the MRSEC program (NSF DMR- 1720139) at the Materials Research Center, the SHyNE Resource (NSF ECCS-1542205), and the Initiative for Sustainability and Energy (ISEN) at Northwestern University.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films