Crystalline CoFeP@Amorphous NiCoP Electrocatalysts with High-Efficient Alkaline Seawater Splitting Performances
The sluggish kinetics and poor stability of single-component electrocatalysts constrain their deployment in alkaline seawater electrolysis. This work reports crystalline CoFeP@amorphous NiCoP composites synthesized via a one-step hydrothermal route followed by phosphidation. The coral-like architecture exposes abundant active sites. The catalyst delivers an overpotential of 356 mV at 500 mA cm−2 for the hydrogen evolution reaction (HER) and 257 mV at 100 mA cm−2 for the oxygen evolution reaction (OER). A two-electrode system employing these materials requires a cell voltage of 1.76 V at 100 mA cm−2. In alkaline seawater, the electrode sustains a cycle life of 150 h at 50 mA cm−2, demonstrating resistance to chloride corrosion and precipitate formation. The crystalline-amorphous interface facilitates electron transfer and regulates intermediate adsorption. These metrics position the composite as a viable non-noble-metal alternative for industrial-scale seawater splitting, though long-term durability at higher current densities and membrane compatibility remain to be validated.