Construction of a High-Efficiency Oxygen Evolution Reaction Catalyst Using V-Doped Synergistic Mott–Schottky Heterostructures

Rationally designing heterostructures with well-regulated electronic environments is desirable to circumvent the sluggish kinetics of the oxygen evolution reaction (OER). Herein, we propose a dual-engineering strategy─combining Fermi-level manipulation via heteroatom doping with Mott–Schottky heterojunction construction─to synthesize 3D hierarchical CoFe LDH/V–Ni3S2 arrays on nickel foam (NF). Mechanistic investigations reveal that vanadium(V) incorporation modulates the electronic structure of metallic Ni3S2, effectively lowering its work function and amplifying the disparity with the p-type semiconducting CoFe LDH. This maximized thermodynamic driving force triggers unidirectional electron transfer from V–Ni3S2 to CoFe LDH, establishing a robust interfacial built-in electric field and spatially separated electrophilic/nucleophilic microdomains. Crucially, this intense interfacial polarization lowers the energy barrier for dynamic structural evolution, accelerating the in situ reconstruction of the CoFe LDH coating into highly catalytic Co/Fe-OOH at merely 1.3 V, while promoting the inner V–Ni3S2 surface to evolve into synergistic NiOOH. Benefiting from the optimized intrinsic activity and accelerated interfacial electron dynamics, the CoFe LDH/V–Ni3S2/NF catalyst delivers outstanding OER performance, attaining the benchmark 10 mA cm–2 at an overpotential of 217 mV, alongside a Tafel slope of 34.4 mV dec–1 in alkaline media. This work elucidates the correlation between interfacial electronic reconfiguration and dynamic phase evolution, providing a rational strategy for designing advanced Mott–Schottky electrocatalysts.