Abstract
AbstractHematite (α-Fe2O3) nanowhiskers (NWs) synthesized via oxidation of iron-based substrates are a promising photoanode material for photoelectrochemical water splitting. Such synthesized α-Fe2O3 NWs have been found to contain ordered axial structures. Herein, we reveal that the known (1$$\overline{1}$$
1
¯
2)-related ordered structure actually exists in bicrystalline α-Fe2O3 NWs instead of single-crystalline α-Fe2O3 NWs and that it is associated with another known (3$$\overline{3}$$
3
¯
0)-related ordered structure. Through a spherical aberration (CS)-corrected high-resolution transmission electron microscopy (HR-TEM) investigation, the microstructural characteristic of the (1$$\overline{1}$$
1
¯
2)-related ordered structure is verified to be periodic atomic column displacements serving as tensile strain accommodation. The HR-TEM observation are also supported by a monochromated O K-edge EELS analysis, which indicates that α-Fe2O3 NWs hosting the (1$$\overline{1}$$
1
¯
2)-related ordered structure are indeed associated with lattice expansion. In sum, our microstructural study elucidates the root cause of the long-asserted relationship between the (1$$\overline{1}$$
1
¯
2)-related ordered structure and oxygen vacancy ordering.
Funder
Ministry of Education, Culture, Sports, Science and Technology
Publisher
Springer Science and Business Media LLC
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science