CoFe-(Oxy)Hydroxide@Co₃O₄-CeO₂ Core–Shell Nanorods on Nickel Foam for Oxygen Evolution Reaction

The development of highly active and cost-effective electrocatalysts, such as transition-metal oxides and (oxy)hydroxides, for the oxygen evolution reaction (OER) is of great importance in water-splitting electrolyzers. Building nanohybrids is an effective strategy to improve the OER activity of transition-metal oxides and (oxy)hydroxides. In this work, we present a feather-like CoFe-(oxy)hydroxide@Co 3 O 4 -CeO 2 3D hierarchical heterostructure on nickel foam (NF) by coupling amorphous CoFe-(oxy)hydroxide on Co 3 O 4 -CeO 2 hybrid nanorods for enhanced OER performance. Owing to the synergistic effect and interface engineering of CoFe-(oxy)hydroxide, Co 3 O 4, and CeO 2, as well as the large electrochemically active surface area with enhanced exposed active sites, the as-prepared CoFe-(oxy)hydroxide@Co 3 O 4 -CeO 2 electrode exhibits superior activity with a required overpotential of 0.228 V to achieve 10 mA cm –2 in 1.0 M KOH, which is among the best values for Co 3 O 4 -based and CoFe-based OER electrocatalysts.