In Situ Electrochemical Formation of a Core‐Shell ZnFe<sub>2</sub>O<sub>4</sub>@Zn(Fe)OOH Heterostructural Catalyst for Efficient Water Oxidation in Alkaline Medium
Richard Appiah‐Ntiamoah, Anteneh F. Baye, Hern Kim
Abstract
Abstract Low‐cost, stable and highly active electrocatalysts for the oxygen evolution reaction (OER) are needed to improve the efficiency of hydrogen production via water splitting. However, developing such a catalyst is still a challenge. Zinc ferrite (ZnFe 2 O 4 ) is non‐toxic and made from cheap and earth‐abundant materials making it a potential raw material for synthesizing “green” low‐cost catalysts for the OER. However, it has largely been ignored due to its low stability, conductivity and OER‐inactive Zn 2+ . Herein, ZnFe 2 O 4 is used effectively as a pre‐catalyst to synthesize core‐shell ZnFe 2 O 4 @Zn(Fe)OOH polycrystalline heterostructures in situ via cyclic voltammetry. The ZnFe 2 O 4 @Zn(Fe)OOH heterostructures display much higher OER catalytic activity and stability than the benchmark RuO 2 catalyst in alkaline medium, owing to its high conductivity, stability and electrochemically active surface area (ECSA). Our findings thus reveal a new and effective way by which ZnFe 2 O 4 can be applied in water electrolysis.