Iron-Doped Nickel Phosphide Nanosheets InSitu Grown on Nickel Submicrowires as Efficient Electrocatalysts for Oxygen Evolution Reaction

Tens of micrometers long metallic Ni submicrowires with a diameter of approximately 200 nm are prepared by a chemical reduction method under a magnetic field. Fe-doped Ni2P nanosheets are then insitu grown on Ni submicrowires by a simple wet-chemical reaction followed by a low-temperature phosphorization process. The (Ni0.87Fe0.13)(2)P-Ni composite exhibits the highest catalytic activity toward oxygen evolution reaction in alkaline solution among all the as-prepared (Ni1-xFex)(2)P-Ni catalysts, delivering a current density of 10 mAcm(-2) at an overpotential of only 257 mV and keeping high stability over 10 h electrolysis. These exceptional activities are attributed to the unique structure combining metallic Ni submicrowires as good electronically conductive substrate and the insitu grown Fe-doped Ni2P nanosheets. Specifically, Fe incorporation leads to strong electron interactions between Ni, Fe, and P, fast reaction kinetics, small charge-transfer resistance, and a large electrochemical surface area, which are responsible for the excellent catalytic performance.