Highly N-Doped Fe/Co Phosphide Superstructures for Efficient Water Splitting

Developing an inexpensive bifunctional electrocatalyst for overall water splitting is critical for acquiring scalable green hydrogen and thereby realizing carbon neutralization. Herein, an all-in-one method is developed for the fabrication of highly N-doped binary FeCo-phosphides (N-FeCoP) with hierarchical superstructure, this delicately designed synthesis route allows the following merits for benefiting water splitting electrocatalysis in alkaline, including high N/defect-doping for mediating the surface property of the as-made N-FeCoP, binary Fe and Co components exhibiting strong coupling interaction, and 3D hierarchical superstructure for shortening diffusion length and thereby improving reaction kinetics. Electrochemical measurements reveal that the N-FeCoP sample exhibits very low overpotentials for initiating the hydrogen and oxygen evolution reactions. Remarkably, overall water splitting can be promoted on N-FeCoP using a commercial primary Zn-MnO2 battery. The developed synthesis strategy may potentially inspire the preparation of other N-doped metal-based nanostructures for broad electrocatalysis.

Automated summary

Developing an inexpensive bifunctional electrocatalyst is crucial for generating scalable green hydrogen and achieving carbon neutrality. In this study, a versatile approach is proposed to synthesize highly N-doped binary FeCo-phosphides (N-FeCoP) with hierarchical superstructure, enabling enhanced water splitting electrocatalysis through high N/defect-doping, strong coupling interaction between Fe and Co components, and a 3D hierarchical superstructure. Electrochemical measurements demonstrate that N-FeCoP exhibits low overpotentials for hydrogen and oxygen evolution reactions. Remarkably, overall water splitting can be achieved on N-FeCoP using a commercial primary Zn-MnO2 battery. This synthesis strategy may inspire the development of other N-doped metal-based nanostructures for a wide range of electrocatalytic applications.