Functionalized 3D Mo₂N Current Collectors Drive Multi‐Phase Ni‐based Synergy and Mitigate Surface Reconstruction for Enhanced Oxygen Evolution Catalysis

Abstract

Electrochemical water splitting is a promising approach for sustainable hydrogen production, but the oxygen evolution reaction (OER) remains a bottleneck due to sluggish kinetics, poor activity, and limited stability and scalability. Here, a Mo₂N-functionalized nickel is designed foam (NF@Mo₂N) and subsequently transform into a Mo₂N/NiSe/Ni₂P multi-phase heterostructure through selenization and phosphorization, to address these challenges. The optimized NF@Mo₂N/NiSe/Ni₂P catalyst integrates three key strategies: (I) functionalizing NF with Mo₂N to enhance conductivity and charge transfer, (II) engineering a collaborative multi-interface heterostructure to optimize active sites and reaction kinetics, and (III) precisely controlling phase formation through selenization and phosphorization to mitigate surface reconstruction and ensure long-term stability. The catalyst not only achieves an overpotential of 242 mV@10 mA cm^-2 and remarkable stability over 350 h, but also achieves a low overpotential of 395 mV at a high current density of 800 mA cm^-2, outperforming the pristine other control samples. Theoretical analysis reveals that the Mo₂N-stabilized NiSe/Ni₂P heterostructure on NF enhances conductivity and optimizes adsorption energies of OER intermediates, leading to improved catalytic performance and stability. This work provides a new strategy for designing high-performance, non-precious metal OER catalysts for industrial applications and advancing sustainable hydrogen production.