Dynamic surface reconstruction of pentlandite catalyst for enhanced water oxidation reaction.

The development of oxygen evolution reaction (OER) electrocatalysts with high performance and cost-effectiveness are essential for several energy conversion and storage applications. Herein, we present a promising pentlandite OER electrocatalyst (Fe, Ni)₉S₈/Fe-Ni₃S₂, thereinto the (Fe, Ni)₉S₈ readily triggers the dynamic surface reconstruction. In-situ characterizations show that the (Fe, Ni)₉S₈/Fe-Ni₃S₂ self-reconstructed to form FeOOH/NiOOH/Ni₃S₂ during the OER process. Accordingly, the theoretical calculations demonstrate that charge redistribution reduces NiO covalency at the multiphase interface, effectively tuning charge distribution between Ni and O and optimizing the adsorption energy of the ^⁎O intermediate. As expected, the reconstructed FeOOH/NiOOH/Ni₃S₂ catalyst exhibits outstanding OER performance, with an overpotential of 246 mV and excellent stability for 100 h at 100 mA cm^-2. This study elucidates the correlation between the dynamic surface reconstruction and enhanced OER activity in the pentlandite electrocatalyst, thus providing a new material for its practical application in alkaline conditions.