Impact Factor:

11.8

DOI number:

10.1002/smll.202402717

Journal:

Small

Abstract:

Investigating the structural evolution and phase transformation of iron oxides is crucial for gaining a deeper understanding of geological changes on diverse planets and preparing oxide materials suitable for industrial applications. In this study, in-situ heating techniques are employed in conjunction with transmission electron microscopy (TEM) observations and ex-situ characterization to thoroughly analyze the thermal solid-phase transformation of akaganéite 1D nanostructures with varying diameters. These findings offer compelling evidence for a size-dependent morphology evolution in akaganéite 1D nanostructures, which can be attributed to the transformation from akaganéite to maghemite (γ-Fe2O3) and subsequent crystal growth. Specifically, it is observed that akaganéite nanorods with a diameter of ∼50 nm transformed into hollow polycrystalline maghemite nanorods, which demonstrated remarkable stability without arresting crystal growth under continuous heating. In contrast, smaller akaganéite nanoneedles or nanowires with a diameter ranging from 20 to 8 nm displayed a propensity for forming single-crystal nanoneedles or nanowires through phase transformation and densification. By manipulating the size of the precursors, a straightforward method is developed for the synthesis of single-crystal and polycrystalline maghemite nanowires through solid-phase transformation. These significant findings provide new insights into the size-dependent structural evolution and phase transformation of iron oxides at the nanoscale.

Co-author:

Yang He, Lili Liu, Duo Song, Libor Kovarik, Mark E. Bowden, Mark Engelhard, Xiaoxu Li, Yingge Du, Quin RS Miller, Chongmin Wang, James J. De Yoreo

First Author:

Xiang Wang

Correspondence Author:

Kevin M. Rosso, Xin Zhang

Discipline:

Engineering

Document Type:

J

Volume:

20

Issue:

46

Page Number:

2402717

Translation or Not:

no

Date of Publication:

2024-08-15

Included Journals:

SCI

Links to published journals:

https://onlinelibrary.wiley.com/doi/full/10.1002/smll.202402717