<p>It is essential to investigate economical and efficient catalysts for water electrolysis to develop clean energy sources. However, the sluggish kinetics and poor stability of single electrode catalyst limit their further applications in water splitting. In this work, we synthesize CoFeP@NiCoP materials consisting of a transition metal phosphide and an amorphous counterpart. The coral-like structure provides rich active sites for catalytic reaction. It delivers 356 mV at 500 mA cm⁻² for HER and 257 mV at 100 mA cm⁻² for OER. The two-electrode system presents a voltage of 1.76 V at 100 mA cm⁻². For alkaline seawater electrolysis, the sample shows a cycle life of 150 h at 50 mA cm⁻². This work proposes a simple strategy for designing advanced electrocatalysts for water splitting.</p>