Abstract
A layered β-NiOOH crystal with undercoordinated facets is an active and economically viable nonnoble catalyst for the oxygen evolution reaction (OER) in alkaline electrolytes. However, it is extremely difficult to enclose the β-NiOOH crystal with undercoordinated facets because of its inevitable crystal transformation to γ-NiOOH, resulting in the exfoliation of the catalytic surfaces. Herein, we demonstrate {111}-faceted Ni octahedra as the parent substrates whose surfaces are easily transformed to catalytically active β-NiOOH during the alkaline OER. Electron microscopic measurements demonstrate that the horizontally stacked β-NiOOH on the surfaces of Ni octahedra has resistance to further oxidation to γ-NiOOH. By contrast, significant crystal transformation and thus the exfoliation of the γ-NiOOH sheets can be observed on the surfaces of Ni cubes and rhombic dodecahedra (RDs). Electrocatalytic measurements show that the β-NiOOH formed on Ni octahedra exhibits highly enhanced OER durability compared to the Ni cubes, Ni RDs, and the state-of-the-art Ir/C catalysts.
Original language | English |
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Pages (from-to) | 10115-10122 |
Number of pages | 8 |
Journal | ACS Applied Materials and Interfaces |
Volume | 10 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2018 Mar 28 |
Bibliographical note
Funding Information:This work was supported by National Research Foundation of Korea grants (NRF-2017-R1A2B3005682 and NRF-2016H1D5A1910726, NRF-2017-R1A6A3A01008861), IBS-R023-D1, and KBSI Project E37300. The authors thank Korea Basic Science Institute (KBSI) for the usage of their HRTEM instrument.
Publisher Copyright:
© 2018 American Chemical Society.
ASJC Scopus subject areas
- General Materials Science