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Mastering Surface Reconstruction of Metastable Spinel Oxides for Better Water Oxidation
Author(s) -
Duan Yan,
Sun Shengnan,
Sun Yuanmiao,
Xi Shibo,
Chi Xiao,
Zhang Qinghua,
Ren Xiao,
Wang Jingxian,
Ong Samuel Jun Hoong,
Du Yonghua,
Gu Lin,
Grimaud Alexis,
Xu Zhichuan J.
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201807898
Subject(s) - spinel , oxygen evolution , water splitting , metastability , materials science , catalysis , density functional theory , chemical physics , octahedron , rational design , oxygen , chemical engineering , chemistry , inorganic chemistry , nanotechnology , computational chemistry , crystallography , crystal structure , electrochemistry , metallurgy , biochemistry , organic chemistry , electrode , photocatalysis , engineering
Developing highly active electrocatalysts for oxygen evolution reaction (OER) is critical for the effectiveness of water splitting. Low‐cost spinel oxides have attracted increasing interest as alternatives to noble metal–based OER catalysts. A rational design of spinel catalysts can be guided by studying the structural/elemental properties that determine the reaction mechanism and activity. Here, using density functional theory (DFT) calculations, it is found that the relative position of O p‐band and M Oh (Co and Ni in octahedron) d‐band center in ZnCo 2− x Ni x O 4 ( x = 0–2) correlates with its stability as well as the possibility for lattice oxygen to participate in OER. Therefore, it is testified by synthesizing ZnCo 2− x Ni x O 4 spinel oxides, investigating their OER performance and surface evolution. Stable ZnCo 2− x Ni x O 4 ( x = 0–0.4) follows adsorbate evolving mechanism under OER conditions. Lattice oxygen participates in the OER of metastable ZnCo 2− x Ni x O 4 ( x = 0.6, 0.8) which gives rise to continuously formed oxyhydroxide as surface‐active species and consequently enhances activity. ZnCo 1.2 Ni 0.8 O 4 exhibits performance superior to the benchmarked IrO 2 . This work illuminates the design of highly active metastable spinel electrocatalysts through the prediction of the reaction mechanism and OER activity by determining the relative positions of the O p‐band and the M Oh d‐band center.