Seawater Splitting Using NiFeP-Embedded Porous Carbon Fibers

Designing efficient and durable nonprecious metal-based electrocatalysts for high-performance seawater splitting is essential for clean energy conversion. Nevertheless, the underlying cause of NiFeP activity, particularly in the oxygen evolution reaction (OER), remains poorly understood. Using a flexible and controllable electrospinning approach, we effectively synthesized bimetallic NiFeP encapsulated in porous carbon nanofibers (PCF). Benefiting from the strong synergistic effects of the mesoporous structures with optimized binary metal components encapsulated in the carbon nanofibers, NiFeP-PCFs exhibit improved OER and hydrogen evolution reaction (HER) performance in alkaline, neutral, and alkaline seawater electrolytes. The electrode exhibits overpotentials of 320 mV and 145 mV at 100 mA cm^-2 for OER and HER, respectively, in 1 M KOH, with excellent durability (100 h at 100 mA cm^-2). Furthermore, NiFeP-PCF requires a voltage of 1.8 V at 100 mA cm^-2 for seawater splitting and can operate stably for over 200 h. Our research holds significant potential for developing efficient non-noble-metal bimetallic electrodes for water and seawater electrolysis.