Oxygen vacancy and heterointerface engineering of Ni3Fe/NiFe2O4 @N-GTs oxygen evolution reaction electrocatalyst for water splitting

Developing highly efficient electrocatalysts for oxygen evolution reaction (OER) plays a key role in accelerating electrochemical water splitting green energy conversion systems. Herein, the dual strategy of incorporating oxygen vacancy and engineering heterointerface was employed for constructing N-doping graphene tubes (N-GTs) supported Ni 3 Fe/NiFe 2 O 4 heterostructure with abundant oxygen vacancies (Ni 3 Fe/NiFe 2 O 4 @N-GTs). Benefit from accelerating reaction kinetics and optimizing adsorption strength for reaction intermediates resulting from the synergistic effect of vacancies introduction and heterointerface formation, the optimized Ni 3 Fe/NiFe 2 O 4 @N-GTs catalyst exhibits remarkably enhanced OER performance with an overpotential of 230 mV to achieve a current density of 10 mA cm −2 , a low Tafel slope of 33 mV dec −1 and 330 h stability at the high current density of 100 mA cm −2 . Meanwhile, the full water splitting cell consisting of the Ni 3 Fe/NiFe 2 O 4 @N-GTs-350 anode and a Pt/C cathode delivers a low cell voltage of 1.58 V at 10 mA cm −2 and presents excellent durability for over 330 h of continuous operation at the current density of 10 mA cm −2 , demonstrating it promising electrocatalyst for potential applications in the hydrogen production field.