Three-Dimensional Amorphous NiCoFe Nanowire@Nanosheets Catalysts for Enhanced Oxygen Evolution Reaction

Rational design of cost-effective and high-efficiency nonprecious oxygen evolution reaction (OER) catalysts for electrochemical water-splitting towards the commercialization of renewable energy conversion technologies remains challenging. Herein, a facile one-step reduction method is proposed to fabricate three-dimensional (3D) amorphous NiCoFe catalysts with nanowires@nanosheets (NiCoFe NW@NSs) core–shell nanostructures. The unique 3D and amorphous features can accelerate the transfer process of relevant active species and provide more accessible active sites. Coupled with synergistic effects resulting from the ternary metals and core–shell nanostructures, the as-prepared Ni1Co1Fe1 NW@NSs exhibits the ultralow overpotential of 220 mV at the current density of 10 mA cm−2 and Tafel slope of 36.42 mV dec−1, which is superior to the benchmark RuO2 catalyst (290 mV and 127.93 mV dec−1). Furthermore, the catalyst displays remarkable long-term stability with negligible degeneration of only 9 mV after 24 h chronopotentiometry test. This work provides insight into the rational design of catalysts to achieve intrinsically high activity and stability in the alkaline electrolyte for water-splitting devices.