Hydrous Nickel Oxide: Redox switching and the oxygen evolution reaction in aqueous alkaline solution
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2012Citation:
Michael E G Lyons, Richard L Doyle, Ian Godwin, Maria O'Brien, Lisa Russell, Hydrous Nickel Oxide: Redox switching and the oxygen evolution reaction in aqueous alkaline solution, Journal Electrochemical Society, 159, 12, 2012, H932 - H944Download Item:
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Abstract:
The redox switching reaction and the oxygen evolution reaction at multi-cycled nickel oxy-hydroxide films in aqueous alkaline
solution are discussed. The hydrous oxide is considered as a porous assembly of interlinked octahedrally coordinated anionic
metal oxyhydroxide surfaquo complexes which form an open network structure. The latter contains considerable quantities of water
molecules which facilitate hydroxide ion discharge at the metal site during active oxygen evolution. The dynamics of redox switching
has been quantified in terms of a diffusive frequency using the Laviron-Aoki diffusion model. Steady state Tafel plot analysis has
been used to elucidate the kinetics and mechanism of oxygen evolution with slopes of ca. 60 mVdec?1 and ca. 120 mVdec?1 at low
and high overpotentials respectively, whereas the reaction order with respect to hydroxide ion activity remains invariant at ca. 1.0 as
the potential is increased. These observations are rationalized in terms of a kinetic scheme involving surfaquo groups.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
SFI/10/IN.1/I2969-Lyons
Author's Homepage:
http://people.tcd.ie/melyonshttp://people.tcd.ie/igodwin
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Journal ArticleCollections:
Series/Report no:
Journal Electrochemical Society159
12
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Nanoscience & Materials , Smart & Sustainable PlanetDOI:
http://dx.doi.org/10.1149/2.078212jesLicences: