Electron‐Penetrating in Heterointerface Engineering for Oxygen Evolution Reaction in Seawater Splitting

Abstract The interfacial electric field ( IEF ) between heterogeneous units plays an important role in the electronic modulation of active centers during oxygen evolution reaction (OER). However, the weak electronic coupling between spatially separated IEF s limits the deep activation of metal sites on the surface of the catalyst. Herein, a proof‐of‐concept strategy is provided that imbed MS 2 (M = Ni 3 Fe) species with high spin Fe orbits into heterogeneous units to promote the electron penetrating between IEF s. By designing a Fe 2 O 3 @MS/MS 2 @MO y model catalyst, the electronic interaction between adjacent IEF s is effectively enhanced for the deep oxidation of bimetals on the surface, breaking the competing relationship between adsorbed evolution mechanism (AEM) and lattice oxygen mechanism (LOM) of catalysts during OER. As a result, the onset overpotential of the synthesized electrode is only 171 mV, and it maintains excellent stability for more than 2300 h at a current density of 10 mA cm −2 in 1 M KOH + 0.5 M NaCl electrolyte.