Flash combustion of Pt-NiCo2O4 heterointerfaces activates lattice-oxygen pathways for efficient water electrolysis

Noble-metal/oxide heterointerfaces offer an effective route to high-performance bifunctional electrocatalysts for alkaline water splitting, but their rapid and controllable construction remains challenging. Herein, we develop a flash combustion strategy to fabricate Pt nanoparticle-decorated NiCo 2 O 4 nanosheet electrodes on nickel foam within ∼10 s. The transient non-equilibrium process simultaneously drives spinel crystallization, confined Pt nucleation, and porous self-supported electrode formation, yielding abundant Pt-NiCo 2 O 4 heterointerfaces. Systematic tuning of Pt loading reveals a volcano-type dependence of activity on interfacial density. XPS and DFT analyses show that interfacial charge transfer simultaneously downshifts the Pt d -band center and lowers the oxygen vacancy formation energy. The first effect optimizes hydrogen adsorption, while the second promotes a lattice-oxygen-mediated OER pathway. Benefiting from these synergistic effects, the optimized Pt 0.5 @NiCo 2 O 4 achieves 100 mA cm −2 at overpotentials of 67 mV for HER and 283 mV for OER. A symmetric electrolyzer further delivers 100 mA cm −2 at 1.57 V with stable operation for 200 h, surpassing the Pt/C‖RuO 2 benchmark. This work provides a fast and scalable strategy for engineering electronically coupled noble-metal/oxide heterointerfaces for efficient alkaline water electrolysis.