Hydrogen generation from electrolyzed water has received extensive attention in the scientific community due to its green and environmentally friendly properties, as well as the high purity of hydrogen produced. However, the slow oxygen evolution reaction (OER) during electrocatalytic water splitting has significantly hampered the development of hydrogen production, posing numerous challenges in its practical application. In this study, a novel three-dimensional (3D) core-shell heterostructure catalyst with crystalline NiMoO₄ nanorods as “core” and amorphous CoFe-LDH nanosheets as “shell” was successfully fabricated on a conductive nickel foam (NF) substrate by using a combination of hydrothermal and electrodeposition strategy. This special 3D core-shell structure fully stimulates the electrocatalytic potential of NiMoO₄ and CoFe-LDH, which greatly enhances the efficiency of the overall water-splitting. Through the synergistic interaction of NiMoO₄ and amorphous CoFe-LDH, the NiMoO₄@CoFe-LDH/NF nanocatalysts generates more active sites and exhibits highly efficient electron transfer ability and excellent OER electrocatalytic activity. Electrochemical tests show that NiMoO₄@CoFe-LDH/NF exhibits the most excellent electrochemical performance when the electrodeposition time is 60 s. The overpotentials η₁₀ and η₁₀₀ at 10 and 100 mA·cm^-2 are only 168 and 216 mV, respectively, which shows a very small Tafel slope and excellent long-term stability. Meanwhile, the overall water-splitting system of NiMoO₄@CoFe-LDH||NiMoO₄ exhibits a low driving voltage, which can produce a current density of 10 mA·cm^-2 at 1.57 V. In conclusion, this work provides new ideas for design and development of efficient catalytic materials for electrolyzed water.