The development of durable and economical electrocatalysts is essential for sustainable hydrogen production from seawater. In this work, a boron-stabilized and fluorine-modified NiFe oxyhydroxide heterostructure (NiFe–BOF(OH)) was directly grown on nickel foam as a self-supported anode for efficient oxygen evolution. The engineered heterostructure enhances electronic properties, charge-transfer kinetics, corrosion resistance, and catalytic stability in alkaline and seawater environments. Combined experimental and theoretical studies reveal that the synergistic effects of boron stabilization, fluorine-induced electronic modulation, and NiFe interfacial coupling promote oxygen evolution while suppressing degradation. This work provides a promising strategy for designing robust electrocatalysts for sustainable green hydrogen production from seawater.