Constructing nanochannels via dense amorphous/crystalline NiFeB/Ni2P heterointerface for ultra-stable oxygen evolution reaction

The sluggish diffusion of proton acceptors within the interlayers of NiFe-based layered hydroxides leads to structural collapse, which poses a huge challenge for developing high-performance electrode materials in the oxygen evolution reaction (OER). Herein, robust nanochannels were constructed by customizing the amorphous/crystalline heterointerface for ultra-stable alkaline OER. Boronized treatment triggers the formation of a NiFeB amorphous layer coating on the surface of the Ni₂P conductive substrate, creating a high density of nanoscale NiFeB-Ni₂P interface. Such amorphous NiFe hydroxides generated by NiFeB alloying reconstruction caused loose internal structure during electrooxidation, allowing accelerated electrolyte ion transport. The robust amorphous/crystalline nanochannels further facilitate the oxidation of Ni, leading to the generation of more unsaturated Ni^3+δ sites, serving as catalytically active centers for reducing the conversion energy barrier of O intermediates. The architecture of NiFeB@Ni₂P/Ni foam integrated electrode achieves a low overpotential of 277 mV at 100 mA cm⁻² and remarkable stability for 1000 h, highlighting an efficient strategy for improving the operating stability of catalysts.