In situ Atomic-Scale Probing of Reduction Dynamics of 2-Dimensional Fe2O3 Nanostructures

Published

December 13, 2016

Author(s)

Wenhui Zhu, Jonathan P. Winterstein, Wei-Chang Yang, Lu Yuan, Renu Sharma, Guangwen Zhou

Abstract

Atomic-scale structure dynamics and phase transformation pathway was probed, in situ, during the reduction of bi-crystalline Fe2O3 nanostructures in H2 by using an environmental transmission electron microscope. It was found that the reduction commenced with the α-Fe2O3  γ-Fe2O3 phase transformation of one part of the bi-crystal, resulting in the formation of a hybrid structure of α-Fe2O3 and γ-Fe2O3. The progression of the phase transformation into the other half of the bi-crystalline Fe2O3 across the bi-crystalline boundary led to the formation of a single crystal phase of γ-Fe2O3 with the concomitant oxygen-vacancy ordering on every third 422} planes, followed by transformation into Fe3O4. Further reduction resulted in the coexistence of Fe3O4, FeO, and Fe via the transformation pathway of Fe3O4  FeO  Fe, accompanied with the formation of a Swiss-cheese-like structure induced by significant volume shrinkage. These results elucidated the atomistic mechanism of the reduction of Fe oxides and demonstrated formation of unique hybrid structures of Fe oxides via tuning the phase transformation pathway.

Citation

ACS Nano

Volume

11

Issue

1

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acsnano.6b06950

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Keywords

α-Fe2O3, reduction, in situ TEM, phase transformation

Citation

Zhu, W. , Winterstein, J. , Yang, W. , Yuan, L. , Sharma, R. and Zhou, G. (2016), In situ Atomic-Scale Probing of Reduction Dynamics of 2-Dimensional Fe2O3 Nanostructures, ACS Nano, [online], https://doi.org/10.1021/acsnano.6b06950, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921669 (Accessed April 25, 2024)