Spectroelectrochemical study of water oxidation on nickel and iron oxyhydroxide electrocatalysts
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Ni/Fe oxyhydroxides are the best performing Earth-abundant electrocatalysts for water oxidation. However, the origin of their remarkable performance is not well understood. Herein, we employ spectroelectrochemical techniques to analyse the kinetics of water oxidation on a series of Ni/Fe oxyhydroxide films: FeOOH, FeOOHNiOOH, and Ni(Fe)OOH (5% Fe). The concentrations and reaction rates of the oxidised states accumulated during catalysis are determined. Ni(Fe)OOH is found to exhibit the fastest reaction kinetics but accumulates fewer states, resulting in a similar performance to FeOOHNiOOH. The later catalytic onset in FeOOH is attributed to an anodic shift in the accumulation of oxidised states. Rate law analyses reveal that the rate limiting step for each catalyst involves the accumulation of four oxidised states, Ni-centred for Ni(Fe)OOH but Fe-centred for FeOOH and FeOOHNiOOH. We conclude by highlighting the importance of equilibria between these accumulated species and reactive intermediates in determining the activity of these materials.
Date Issued
2019-11-15
Date Acceptance
2019-10-16
Citation
Nature Communications, 2019, 10
ISSN
2041-1723
Publisher
Nature Research (part of Springer Nature)
Journal / Book Title
Nature Communications
Volume
10
Copyright Statement
© 2019 The Author(s). This article is licensed under a Creative Commons Attri-bution 4.0 International License, which permits use, sharing, adaptation,distribution and reproduction in any medium or format, as long as you give appropriatecredit to the original author(s) and the source, provide a link to the Creative Commonslicense, and indicate if changes were made. The images or other third party material in thisarticle are included in the article’s Creative Commons license, unless indicated otherwise ina credit line to the material. If material is not included in the article’sCreativeCommonslicense and your intended use is not permitted by statutory regulation or exceeds thepermitted use, you will need to obtain permission directly from the copyright holder. Toview a copy of this license, visithttp://creativecommons.org/licenses/by/4.0/.
Sponsor
Commission of the European Communities
Grant Number
732840
Publication Status
Published
Article Number
ARTN 5208