Preparation and phase transition of FeOOH nanorods: strain effects on catalytic water oxidation.
The evolution of the phase and morphology of FeOOH nanorods prepared by a hydrothermal method is studied via X-ray diffraction (XRD) and in situ transmission electron microscopy. The FeOOH nanorod with a tetragonal structure (β-FeOOH) is gradually converted into a rhombohedral Fe2O3nanorod by a simple thermal treatment. The existence of an intermediate FeOOH structure with high lattice strains during the phase transition is identified by Rietveld analysis using XRD. The electrochemical properties of the nanorods are investigated based on the crystal phases to elucidate their relative catalytic activities. The strained-FeOOH nanorods exhibited enhanced catalytic water oxidation activity and stability. Typically, the strained-FeOOH nanorods showed high electrochemical stability under neutral conditions, while tetragonal FeOOH nanorods under the same conditions showed rapid deactivation for water oxidation reaction.
Department of Chemistry, Mokpo National University, Muan-gun, Jeonnam 1666 Yeongsan-ro, Cheonggye-myeon, Muan-gun, Jeonnam 58554, Republic of Korea. namkimin.chem@gmail.com.
Gisang
G
Park
Korea Research Institute of Standard and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.
Yong-Il
http://orcid.org/0000-0002-7851-3610
YI
Kim
Korea Research Institute of Standard and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.
Young Heon
http://orcid.org/0000-0002-6350-6303
YH
Kim
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea. hsong@kaist.ac.kr.
Mira
M
Park
Department of Chemistry, Mokpo National University, Muan-gun, Jeonnam 1666 Yeongsan-ro, Cheonggye-myeon, Muan-gun, Jeonnam 58554, Republic of Korea. namkimin.chem@gmail.com.
Kyu Yeon
KY
Jang
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea. hsong@kaist.ac.kr.
Hyunjoon
H
Song
Department of Chemistry, Mokpo National University, Muan-gun, Jeonnam 1666 Yeongsan-ro, Cheonggye-myeon, Muan-gun, Jeonnam 58554, Republic of Korea. namkimin.chem@gmail.com.
Ki Min
http://orcid.org/0000-0003-1718-5876
KM
Nam