Three-dimensional nickel nanowires modified by amorphous Fe nanosheets as electrocatalysts for the oxygen evolution reaction.

The development of electrode materials with abundant active surface sites is important for large-scale hydrogen production by water electrolysis. In this study, Fe/Ni NWs/NF catalysts were prepared by hydrothermal and electrochemical deposition of iron nanosheets on nickel chain nanowires, initially grown on nickel foam. The synthesized Fe/Ni NWs/NF electrode possessed a 3D layered heterostructure and crystalline-amorphous interfaces, containing amorphous Fe nanosheets, which demonstrated excellent activity in the oxygen evolution reaction (OER). The newly prepared electrode material has a large specific surface area, and its electrocatalytic performance is characterized by a small Tafel slope and an oxygen evolution overpotential of 303 mV at 50 mA cm -2 . The electrode was highly stable in alkaline media with no degradation observed after 40 h of continuous OER operation at 50 mA cm -2 . The study demonstrates the significant promise of the Fe/Ni NWs/NF electrode material for large-scale hydrogen production by water electrolysis and provides a facile and low-cost approach for the preparation of highly active OER electrocatalysts.