Na_0.86Co_0.95Fe_0.05O₂ Layered Oxide As Highly Efficient Water Oxidation Electrocatalyst in Alkaline Media

Electrochemical energy storage and conversion technologies, such as water-splitting devices, rechargeable metal-air batteries, and regenerative fuel cells, are promising alternatives to traditional nonrenewable energy systems. Given the sluggish oxygen evolution reaction (OER) in the above renewable-energy technologies, the development of efficient OER electrocatalysts with high performance is of great importance. Here, we demonstrate a layer-structured oxide Na 0.86 Co 0.95 Fe 0.05 O 2 (NCF0.05) as a novel electrocatalyst for efficient water oxidation in alkaline media. NCF0.05 shows enhanced performance, including lower overpotential, lower Tafel slope and better stability than the parent Na 0.86 CoO 2 (NC). Especially, the OER performance of NCF0.05 is comparable to the state-of-the-art IrO 2 catalyst. This enhanced catalytic activity of NCF0.05 may be ascribed to the unusual synergistic interplay between Fe and Co. A possible dual-metal-site mechanism was also proposed for OER on NCF0.05.