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OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates
The anodic reaction of oxygen evolution reaction (OER), an important point for electrolysis, however, remains the obstacle due to its complicated reaction at electrochemical interfaces. Iridium oxide (IrO(2)) is the only currently known 5d transition metal oxide possessing admirable OER activity. Tr...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5133550/ https://www.ncbi.nlm.nih.gov/pubmed/27910932 http://dx.doi.org/10.1038/srep38429 |
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author | Sun, Wei Liu, Ji-Yuan Gong, Xue-Qing Zaman, Waqas-Qamar Cao, Li-Mei Yang, Ji |
author_facet | Sun, Wei Liu, Ji-Yuan Gong, Xue-Qing Zaman, Waqas-Qamar Cao, Li-Mei Yang, Ji |
author_sort | Sun, Wei |
collection | PubMed |
description | The anodic reaction of oxygen evolution reaction (OER), an important point for electrolysis, however, remains the obstacle due to its complicated reaction at electrochemical interfaces. Iridium oxide (IrO(2)) is the only currently known 5d transition metal oxide possessing admirable OER activity. Tremendous efforts have been carried out to enhance the activity of iridium oxides. Unfortunately there lies a gap in understanding what factors responsible for the activity in doped IrO(2) or the novel crystal structure. Based on two metallic pyrochlores (Bi(2)Ir(2)O(7) and Pb(2)Ir(2)O(6.5)) and IrO(2). It has been found that there exists a strong correlation between the specific OER activity and IrO(6) coordination geometry. The more distortion in IrO(6) geometry ascends the activity of Ir sites, and generates activity order of Pb-Ir > IrO(2) > Bi-Ir. Our characterizations reveal that distorted IrO(6) in Pb-Ir induces a disappearance of J = 1/2 subbands in valence band, while Bi-Ir and IrO(2) resist this nature probe. The performed DFT calculations indicated the distortion in IrO(6) geometry can optimize binding strength between Ir-5d and O-2p due to broader d band width. Based on this insight, enhancement in OER activity is obtained by effects that change IrO(6) octahedral geometry through doping or utilizing structural manipulation with nature of distorted octahedral coordination. |
format | Online Article Text |
id | pubmed-5133550 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-51335502017-01-27 OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates Sun, Wei Liu, Ji-Yuan Gong, Xue-Qing Zaman, Waqas-Qamar Cao, Li-Mei Yang, Ji Sci Rep Article The anodic reaction of oxygen evolution reaction (OER), an important point for electrolysis, however, remains the obstacle due to its complicated reaction at electrochemical interfaces. Iridium oxide (IrO(2)) is the only currently known 5d transition metal oxide possessing admirable OER activity. Tremendous efforts have been carried out to enhance the activity of iridium oxides. Unfortunately there lies a gap in understanding what factors responsible for the activity in doped IrO(2) or the novel crystal structure. Based on two metallic pyrochlores (Bi(2)Ir(2)O(7) and Pb(2)Ir(2)O(6.5)) and IrO(2). It has been found that there exists a strong correlation between the specific OER activity and IrO(6) coordination geometry. The more distortion in IrO(6) geometry ascends the activity of Ir sites, and generates activity order of Pb-Ir > IrO(2) > Bi-Ir. Our characterizations reveal that distorted IrO(6) in Pb-Ir induces a disappearance of J = 1/2 subbands in valence band, while Bi-Ir and IrO(2) resist this nature probe. The performed DFT calculations indicated the distortion in IrO(6) geometry can optimize binding strength between Ir-5d and O-2p due to broader d band width. Based on this insight, enhancement in OER activity is obtained by effects that change IrO(6) octahedral geometry through doping or utilizing structural manipulation with nature of distorted octahedral coordination. Nature Publishing Group 2016-12-02 /pmc/articles/PMC5133550/ /pubmed/27910932 http://dx.doi.org/10.1038/srep38429 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Sun, Wei Liu, Ji-Yuan Gong, Xue-Qing Zaman, Waqas-Qamar Cao, Li-Mei Yang, Ji OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title | OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title_full | OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title_fullStr | OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title_full_unstemmed | OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title_short | OER activity manipulated by IrO(6) coordination geometry: an insight from pyrochlore iridates |
title_sort | oer activity manipulated by iro(6) coordination geometry: an insight from pyrochlore iridates |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5133550/ https://www.ncbi.nlm.nih.gov/pubmed/27910932 http://dx.doi.org/10.1038/srep38429 |
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