MOF-Derived Ni2P with Stable HER/OER Properties Toward Large-Current Water Splitting and Long-Life Zinc-Air Battery

Electrocatalytic overall water splitting (OWS) and rechargeable zinc-air batteries (ZABs) have emerged as core research focuses on the field of energy conversion and storage. Herein, a nickel foam (NF)-supported MOF-derived Ni2P composite was fabricated via a facile two-step strategy involving a one-pot oil-bath reaction followed by a solid-state reaction. The resulting Ni2P/NF possesses a larger electrochemical active surface area and faster charge transfer activity compared with the Ni-BDC/NF precursor. Benefiting from its favorable intrinsic electrocatalytic properties, the synthesized Ni2P/NF exhibits an industrial-grade water-splitting activity with a current density exceeding 1.0 A cm–2 and can be directly utilized as an air cathode for the assembly of rechargeable ZABs. Specifically, the Ni2P/NF catalyst requires low overpotentials of 508.6 mV for the hydrogen evolution reaction (HER) and 501 mV for the oxygen evolution reaction (OER) to achieve a high current density of 1.0 A cm–2. Furthermore, Ni2P/NF can directly serve as a functional air-cathode material for liquid-state ZAB fabrication. Notably, a series connection of two Ni2P/NF-based ZABs can act as a sustainable power source to successfully light up a LED panel and drive a two-electrode water-splitting device. Accordingly, the as-fabricated Ni2P/NF serves as a high-efficiency catalyst for self-powered hydrogen production. This work not only provides a cost-effective alternative catalyst for large-current-density water splitting but also offers valuable experimental guidance for the rational design and development of advanced high-efficiency bifunctional electrocatalysts.