In the oxygen evolution reaction (OER), it is discovered that introducing defects into Ni-based electrocatalysts can effectively enhance their catalytic activity. However, the specific structure of these defects and their role in modulating the performance of electrocatalysts remain unclear. Herein, an innovative core-shell nano-heterogeneous catalyst is reported that significantly boosts water decomposition efficiency through a strategy combining dynamic surface pre-reconfiguration and selenization. The Ni3Mo-reconstruction@MoSe2/NiSe2 (NM-Re@MS/NS) core-shell heterogeneous catalyst is designed and synthesized. The surface pre-reconstruction technique is employed to adjust the element distribution and induce the catalyst to form a more active surface phase. The MoSe2/NiSe2 (MS/NS) modulates the electronic structure and surface chemistry of the catalyst, thereby facilitating the adsorption/desorption of OH⁻ and *H. As anticipated, NM-Re@MS/NS exhibited excellent catalytic activity for both the OER and hydrogen evolution reaction (HER) in 1.0 M KOH (OER: 258 mV@300 mA cm⁻2; HER: 65 mV@10 mA cm⁻2), with notable stability (OER: 80 h@250 mA cm⁻2; HER: 63h@250 mA cm⁻2). Importantly, in OER || HER system, the NM-Re@MS/NS catalyst, acting as both cathode and anode, exhibits an overpotential of 284 mV at 300 mA cm⁻2, significantly increasing the rates of hydrogen and oxygen production.
Keywords: core‐shell heterogeneous interface; dynamic reconstruction; electronic structure regulation; hydrogen evolution reaction; oxygen evolution reaction.
© 2025 Wiley‐VCH GmbH.