Electrochemical synergy between FeNi nanoalloy@tungsten carbide on N-doped graphitized carbon layers as an excellent electrocatalyst for oxygen evolution reaction

Reasonable construction of non-noble metal-based catalysts as a substitute to precious metal-based catalysts for the oxygen evolution reaction (OER) in water splitting has been a challenge. Herein, ultrasmall core-shell-structured FeNi encapsulated within tungsten carbide (WC) stabilized in a thin N-doped graphitized carbon layer (NCL) was proposed through a unique one-step encapsulation strategy combined with a high temperature carbonization procedure and tested as an OER catalyst. Physicochemical characterizations of the newly prepared material demonstrate that metal nanoparticles are embedded in the carbon layers of FeNi@WC-NCL, which possess a highly porous structure and large specific surface area. By modulating the electronic effects of both the FeNi alloy and WC, the optimal NiFe@WC-NCL catalyst presents excellent performance with an onset potential of 1.38 V (vs. RHE) and an overpotential of only 279 mV (vs. RHE) at the current density of 10 mA cm −2 towards OER. Moreover, NiFe@WC-NCL exhibits excellent durability after 2000 cycles with a slight overpotential decrease of only 11 mV. Both the property and stability of the proposed catalyst surpass the benchmark RuO 2 catalyst, providing great potential as an alternative to precious metal catalysts for the OER.