NiFe-based transition metal catalysts are widely used in electrocatalysis, especially in the field of water splitting, due to their excellent electrochemical performance. Herein, a simple method was ...designed to synthesize a Ni MOF based on nickel foam and it was modified with Fe. After the introduction of Fe, the resulting material exhibits an obvious yolk-shell structure, which greatly increases the specific surface area and facilitates the construction of active sites. At the same time, the synergy between Ni and Fe is conducive to optimizing the electronic structure and effectively improving the poor stability of the MOF. As a result, the synthesized Ni MOF-Fe-2 only needs an overpotential of 229 mV to achieve the OER at a current density of 10 mA cm
−2
, which is better than most reported transition metal-based electrocatalysts. To our surprise, it showed extraordinary stability under the voltage used for water splitting.
The yolk-shell structure of Ni MOF-Fe-2 shows ultra-high stability in water splitting under a high current density and is expected to become an efficient catalyst for the production of clean energy.
Metal-organic-frameworks (MOFs) are scarcely considered to catalyse electrochemical reactions directly due to the limitation of their bulk structure, poor conductivity, and scarce active sites. Fe ...ions, as effective activity boosters for nickel-based catalysts, can effectively modulate the neatly arranged structure and electron configuration of MOF materials through the penetrating and etching process. Therefore, a Fe ion etching method was employed to modulate the structure and electronic configuration of bulk MOF. The resulting Ni-MOF-Fe-2 was equipped with a wider pore width distribution and lower crystallinity, and the Fe ion doping induced many dislocations and stacking faults in the lattice planes, which provided sufficient defects and active sites for OER. Therefore, Ni-MOF-Fe-2 displayed an advanced performance with an overpotential of 269 mV at the current density of 10 mA cm
−2
, and the small Tafel slope of 47.1 mV dec
−1
and charge transfer resistances (
R
ct
) of 8.31 Ω revealed its fast kinetics and high electron transfer efficiency, indicating that Fe ion etching played an important role in booting OER performance of Ni MOF.
In this work, Ni-MOF-Fe-2 was fabricated by using Fe
3+
etching bulk Ni MOF, and the as-prepared catalyst showed significantly enhanced OER performances, which exhibited a low overpotential (η
10
= 269 mV) and remarkable durability in 1 M KOH.
