Highly Efficient Oxygen Evolution Reaction Enabled by Phosphorus Doping of the Fe Electronic Structure in Iron-Nickel Selenide Nanosheets.

The electronic structure of active sites is critically important for electrochemical reactions. Here, the authors report a facile approach to independently regulate the electronic structure of Fe in Ni0.75 Fe0.25 Se2 by P doping. The resulting electrode exhibits superior catalytic performance for the oxygen evolution reaction (OER) showing a low overpotential (238 mV at 100 mA cm-2 , 185 mV at 10 mA cm-2 ) and an impressive durability in an alkaline medium. Additionally, the mass activity of 328.19 A g-1 and turnover frequency (TOF) of 0.18 s-1 at an overpotential of 500 mV are obtained for P─Ni0.75 Fe0.25 Se2 which is much higher than that of Ni0.75 Fe0.25 Se2 and RuO2 . This work presents a new strategy for the rational design of efficient electrocatalysts for OER.