Asymmetric 3d Electronic Structure for Enhanced Oxygen Evolution Catalysis

The oxygen evolution reaction (OER) is an essential process for renewable energy, and designing a bifunctional oxygen electrocatalyst with high catalytic performance plays a significant role. In this work, FeS, Ni₃S₂, Fe₅Ni₄S₈, and N, O, S-doped meshy carbon base were successfully synthesized. The sample containing Fe₅Ni₄S₈ exhibited excellent OER performance. The density functional theory calculations indicate that the partial density of states for 3d electrons (3d-PDOS) of Fe and Ni atoms are changed from monometallic sulfide to bimetallic sulfide at the sulfur vacancy. The asymmetric 3d electronic structure optimizes the 3d-PDOS of Fe and Ni atoms, and leads to an enhanced OER activity. This work provides a new strategy to prepare a low-cost electrocatalyst for oxygen evolution with high-efficiency