FeNi3–FeNi3N – a high-performance catalyst for overall water splitting

Abstract

The design and development of non-precious metal catalysts with high activity and stability for overall water splitting remains a major challenge. Herein, lamellar FeNi₃N incorporated by FeNi₃ is synthesized via thermal ammonolysis. The abundance of hollow sites in this FeNi₃–FeNi₃N heterostructure significantly enhances the intrinsic activity towards hydrogen evolution reaction, while the heterostructure also offers high electrochemical active surface area for oxygen evolution reaction. FeNi₃–FeNi₃N enables a lower overpotential for both hydrogen and oxygen evolution electrocatalysis in alkaline media. When FeNi₃–FeNi₃N is employed as a bifunctional material for overall water splitting, it shows a cell voltage of only 1.5 V at 10 mA cm⁻² and offers stable performance for up to 48 h at current densities of ∼40 mA cm⁻².