Structural refinement and density functional theory study of synthetic Ge-akaganéite (β-FeOOH)

Donghoon Chung; Changyun Park; Woohyun Choi; Yungoo Song

doi:10.3390/cryst10040239

Structural refinement and density functional theory study of synthetic Ge-akaganéite (β-FeOOH)

Donghoon Chung, Changyun Park, Woohyun Choi, Yungoo Song

School of Earth System Sciences

Yonsei University

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

In this study, we propose a revised structural model for highly ordered synthetic Ge-akaganéite, a stable analogue of tunnel-type Fe-oxyhydroxide, based on the Rietveld refinement of synchrotron X-ray diffraction data and density functional theory with dispersion correction (DFT-D) calculations. In the proposed crystal structure of Ge-akaganéite, Ge is found not only in the tunnel sites as GeO(OH)₃ ⁻ tetrahedra, but also 4/5 of total Ge atoms are in the octahedral sites substituting 1/10 of Fe. In addition, the tunnel structures are stabilized by the presence of hydrogen bonds between the framework OH and Cl⁻ species, forming a twisted cube structure and the GeO(OH)₃ ⁻ tetrahedra corner oxygen, forming a conjugation bond. The chemical formula of the synthetic Ge-akaganéite was determined to be (Fe_7.2Ge_0.8)O_8.8(OH)_7.2Cl_0.8(Ge(OH)₄)_0.2.

Original language	English
Article number	239
Journal	Crystals
Volume	10
Issue number	4
DOIs	https://doi.org/10.3390/cryst10040239
State	Published - Apr 2020

Keywords

DFT-D
Ge-akaganéite
Synchrotron XRD
Tunnel structure

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@article{66ec98a426494b1aaa647c1980be7217,

title = "Structural refinement and density functional theory study of synthetic Ge-akagan{\'e}ite (β-FeOOH)",

abstract = "In this study, we propose a revised structural model for highly ordered synthetic Ge-akagan{\'e}ite, a stable analogue of tunnel-type Fe-oxyhydroxide, based on the Rietveld refinement of synchrotron X-ray diffraction data and density functional theory with dispersion correction (DFT-D) calculations. In the proposed crystal structure of Ge-akagan{\'e}ite, Ge is found not only in the tunnel sites as GeO(OH)3 − tetrahedra, but also 4/5 of total Ge atoms are in the octahedral sites substituting 1/10 of Fe. In addition, the tunnel structures are stabilized by the presence of hydrogen bonds between the framework OH and Cl− species, forming a twisted cube structure and the GeO(OH)3 − tetrahedra corner oxygen, forming a conjugation bond. The chemical formula of the synthetic Ge-akagan{\'e}ite was determined to be (Fe7.2Ge0.8)O8.8(OH)7.2Cl0.8(Ge(OH)4)0.2.",

keywords = "DFT-D, Ge-akagan{\'e}ite, Synchrotron XRD, Tunnel structure",

author = "Donghoon Chung and Changyun Park and Woohyun Choi and Yungoo Song",

note = "Publisher Copyright: {\textcopyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland.",

year = "2020",

month = apr,

doi = "10.3390/cryst10040239",

language = "English",

volume = "10",

journal = "Crystals",

issn = "2073-4352",

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TY - JOUR

T1 - Structural refinement and density functional theory study of synthetic Ge-akaganéite (β-FeOOH)

AU - Chung, Donghoon

AU - Park, Changyun

AU - Choi, Woohyun

AU - Song, Yungoo

PY - 2020/4

Y1 - 2020/4

N2 - In this study, we propose a revised structural model for highly ordered synthetic Ge-akaganéite, a stable analogue of tunnel-type Fe-oxyhydroxide, based on the Rietveld refinement of synchrotron X-ray diffraction data and density functional theory with dispersion correction (DFT-D) calculations. In the proposed crystal structure of Ge-akaganéite, Ge is found not only in the tunnel sites as GeO(OH)3 − tetrahedra, but also 4/5 of total Ge atoms are in the octahedral sites substituting 1/10 of Fe. In addition, the tunnel structures are stabilized by the presence of hydrogen bonds between the framework OH and Cl− species, forming a twisted cube structure and the GeO(OH)3 − tetrahedra corner oxygen, forming a conjugation bond. The chemical formula of the synthetic Ge-akaganéite was determined to be (Fe7.2Ge0.8)O8.8(OH)7.2Cl0.8(Ge(OH)4)0.2.

AB - In this study, we propose a revised structural model for highly ordered synthetic Ge-akaganéite, a stable analogue of tunnel-type Fe-oxyhydroxide, based on the Rietveld refinement of synchrotron X-ray diffraction data and density functional theory with dispersion correction (DFT-D) calculations. In the proposed crystal structure of Ge-akaganéite, Ge is found not only in the tunnel sites as GeO(OH)3 − tetrahedra, but also 4/5 of total Ge atoms are in the octahedral sites substituting 1/10 of Fe. In addition, the tunnel structures are stabilized by the presence of hydrogen bonds between the framework OH and Cl− species, forming a twisted cube structure and the GeO(OH)3 − tetrahedra corner oxygen, forming a conjugation bond. The chemical formula of the synthetic Ge-akaganéite was determined to be (Fe7.2Ge0.8)O8.8(OH)7.2Cl0.8(Ge(OH)4)0.2.

KW - DFT-D

KW - Ge-akaganéite

KW - Synchrotron XRD

KW - Tunnel structure

UR - http://www.scopus.com/inward/record.url?scp=85082806728&partnerID=8YFLogxK

U2 - 10.3390/cryst10040239

DO - 10.3390/cryst10040239

M3 - Article

AN - SCOPUS:85082806728

SN - 2073-4352

VL - 10

JO - Crystals

JF - Crystals

IS - 4

M1 - 239

ER -

Structural refinement and density functional theory study of synthetic Ge-akaganéite (β-FeOOH)

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Keywords

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