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Hierarchically Structured NiFeO x /CuO Nanosheets/Nanowires as an Efficient Electrocatalyst for the Oxygen Evolution Reaction
Author(s) -
Czioska Steffen,
Wang Jianying,
Zuo Shangshang,
Teng Xue,
Chen Zuofeng
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201701441
Subject(s) - overpotential , tafel equation , oxygen evolution , electrocatalyst , materials science , nanosheet , calcination , chemical engineering , catalysis , electrolysis , nanowire , water splitting , inorganic chemistry , electrolysis of water , nanotechnology , electrolyte , electrode , electrochemistry , chemistry , photocatalysis , organic chemistry , engineering
It is desirable to fabricate hierarchically structured NiFe‐based materials to further boost the performance of these state‐of‐the‐art electrocatalysts for the oxygen evolution reaction (OER). Most of the NiFeO x catalysts in the form of layered double hydroxides feature a nanosheet structure, which limits their spatial extension at the electrode substrate. Herein, we report the fabrication of unique NiFeO x /CuO nanosheets/nanowires and their use as efficient electrocatalysts for the OER. The surface‐bound Cu(OH) 2 nanowires were grown in situ on a copper substrate by a simple solution‐based method, which were then converted to CuO nanowires by calcination in air. The coating of NiFeO x nanosheets was achieved by anodic co‐deposition in concentrated carbonate solution containing Ni II and Fe III . The presence of concentrated carbonate anions allows Fe III to be dissolved in a basic solution by complex ion formation. This strategy therefore avoids the destruction of CuO nanowires caused by the usual cathodic procedure in acidic solutions. At a planar copper foil, a small Tafel slope of 36 mV dec −1 was obtained in 1 m KOH and a current density of 100 mA cm −2 was reached at a very low overpotential of 300 mV from the Tafel plot. Electrolysis experiments showed high stability of the catalyst with nearly no loss in efficiency and morphology change after a prolonged period. The same catalyst could be established on a three‐dimensional copper foam.