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Layered Structure Causes Bulk NiFe Layered Double Hydroxide Unstable in Alkaline Oxygen Evolution Reaction
Author(s) -
Chen Rong,
Hung SungFu,
Zhou Daojin,
Gao Jiajian,
Yang Cangjie,
Tao Huabing,
Yang Hong Bin,
Zhang Liping,
Zhang Lulu,
Xiong Qihua,
Chen Hao Ming,
Liu Bin
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.201903909
Subject(s) - oxygen evolution , materials science , layered double hydroxides , hydroxide , electrochemistry , dissolution , chemical engineering , diffusion , catalysis , oxygen , inorganic chemistry , electrode , chemistry , organic chemistry , physics , engineering , thermodynamics
NiFe‐based layered double hydroxides (LDHs) are among the most efficient oxygen evolution reaction (OER) catalysts in alkaline medium, but their long‐term OER stabilities are questionable. In this work, it is demonstrated that the layered structure makes bulk NiFe LDH intrinsically not stable in OER and the deactivation mechanism of NiFe LDH in OER is further revealed. Both operando electrochemical and structural characterizations show that the interlayer basal plane in bulk NiFe LDH contributes to the OER activity, and the slow diffusion of proton acceptors (e.g., OH − ) within the NiFe LDH interlayers during OER causes dissolution of NiFe LDH and therefore decrease in OER activity with time. To improve diffusion of proton acceptors, it is proposed to delaminate NiFe LDH into atomically thin nanosheets, which is able to effectively improve OER stability of NiFe LDH especially at industrial operating conditions such as elevated operating temperatures (e.g., at 80 °C) and large current densities (e.g., at 500 mA cm −2 ).