Ni3Fe nanoparticles encapsulated by N-doped carbon derived from MOFs for oxygen evolution reaction

Abstract

It has been a hot research topic to look for inexpensive alternative oxygen evolution reaction (OER) catalysts to replace noble metal-based materials due to their scarcity. Transition metals are ideal candidates because of their high abundance, impressive activities, and easy accessibility. However, a facile method leading to improved performance and stability is still needed. Herein, a highly efficient carbon-encapsulated bimetal catalyst derived from Ni-based metal-organic-frameworks (MOF) was successfully prepared through the low-temperature (350 ℃) pyrolysis of Prussian blue analogue (PBA) precursors under H 2 /Ar atmosphere. Cube-structured PBA as template and precursor，parameters during the pyrolysis process including temperature and calcination atmosphere can be tuned to control the structure and properties of the catalysts. Benefiting from the porous three-dimensional (3D) cubic structure and abundant defect-rich amorphous N-doped carbon shell, Ni 3 Fe@NC-350 exhibits excellent OER activity. The as-prepared catalysts exhibited excellent catalytic performance for OER in 1.0 M KOH with an overpotential of 237 mV to achieve 10 mA cm −2 . More importantly, the presented catalyst has an extremely good durability. • A simple low-temperature annealing method was developed to produce alloy encapsulated with N-doping carbon. • The NiFe PBA was employed as nitrogen and carbon source. • The increased activity of OER is due to the synergy of Ni 3 Fe alloy and N-doped carbon layer. • Theoretical calculations revealed that the synergistic effect of NiFe alloy nanoparticles and N-doped carbon layer.