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Engineering Bimetal Synergistic Electrocatalysts Based on Metal–Organic Frameworks for Efficient Oxygen Evolution
Author(s) -
Liu Ming,
Kong Lingjun,
Wang Xuemin,
He Jie,
Bu XianHe
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201903410
Subject(s) - overpotential , oxygen evolution , bimetallic strip , catalysis , bimetal , materials science , electrochemistry , ionic liquid , hydroxide , electrolyte , chemical engineering , metal organic framework , ionic bonding , inorganic chemistry , chemistry , electrode , ion , organic chemistry , composite material , adsorption , engineering
Benefiting from metal–organic frameworks (MOFs) unique structural characteristics, their versatility in composition and structure has been well explored in electrochemical oxygen evolution reaction (OER) processes. Here, a ligand/ionic exchange phenomenon of MOFs is reported in alkaline solution due to their poor stability, and the active species and reaction mechanism of MOFs are revealed in the OER process. A series of mixed Ni‐MOFs and Fe‐MOFs are synthesized by straightforward sonication and then directly used as catalyst candidates for OER in alkaline electrolyte. It can be confirmed via ex situ transmission electron microscopic images and X‐ray diffraction patterns analysis, that the bimetallic hydroxide (NiFe‐LDH) is generated in 1.0 m KOH in situ and acts as protagonist for oxygen evolution. The optimized catalyst (FN‐2) exhibits a lower overpotential (275 mV at a current density of 10 mA cm −2 ) and excellent long‐term stability (strong current density for 100 h without fading). The revelation of the real active species of MOF materials may contribute to better understanding of the reaction mechanism.