Enlarged Co-O Covalency in Octahedral Sites Leading to Highly Efficient Spinel Oxides for Oxygen Evolution Reaction

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Ye Zhou
  • Shengnan Sun
  • Jiajia Song
  • Shibo Xi
  • Bo Chen
  • Yonghua Du
  • Adrian C. Fisher
  • Fangyi Cheng
  • Zhichuan J. Xu

Detail(s)

Original languageEnglish
Article number1802912
Journal / PublicationAdvanced Materials
Volume30
Issue number32
Online published25 Jun 2018
Publication statusPublished - 9 Aug 2018
Externally publishedYes

Abstract

Cobalt-containing spinel oxides are promising electrocatalysts for the oxygen evolution reaction (OER) owing to their remarkable activity and durability. However, the activity still needs further improvement and related fundamentals remain untouched. The fact that spinel oxides tend to form cation deficiencies can differentiate their electrocatalysis from other oxide materials, for example, the most studied oxygen-deficient perovskites. Here, a systematic study of spinel ZnFexCo2−xO4 oxides (x = 0–2.0) toward the OER is presented and a highly active catalyst superior to benchmark IrO2 is developed. The distinctive OER activity is found to be dominated by the metal–oxygen covalency and an enlarged Co-O covalency by 10–30 at% Fe substitution is responsible for the activity enhancement. While the pH-dependent OER activity of ZnFe0.4Co1.6O4 (the optimal one) indicates decoupled proton–electron transfers during the OER, the involvement of lattice oxygen is not considered as a favorable route because of the downshifted O p-band center relative to Fermi level governed by the spinel's cation deficient nature.

Research Area(s)

  • cation deficiency, decoupled proton–electron transfers, metal–oxygen covalency, oxygen evolution reaction, spinel oxides

Citation Format(s)

Enlarged Co-O Covalency in Octahedral Sites Leading to Highly Efficient Spinel Oxides for Oxygen Evolution Reaction. / Zhou, Ye; Sun, Shengnan; Song, Jiajia et al.
In: Advanced Materials, Vol. 30, No. 32, 1802912, 09.08.2018.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review