Interface coupling effect enhances the alkaline water splitting performance of amorphous NiFeCoP/PPy/NF hybrid electrocatalyst

The growing demand for green hydrogen in the low-altitude economy calls for efficient and durable electrocatalysts. Herein, an amorphous NiFeCoP layer with a polypyrrole (PPy) interlayer was constructed on nickel foam via a two-step electrodeposition method. The PPy interlayer improves interfacial adhesion and electron transport, while amorphous NiFeCoP provides abundant active sites. Owing to this synergistic design, NFCP/PPy/NF exhibits excellent bifunctional activity in alkaline media, requiring only 15.1 mV for HER and 242.4 mV for OER at 10 mA cm −2 . It also shows remarkable durability, maintaining stable HER for 300 h and OER for 100 h. In overall water splitting, the NFCP/PPy/NF||NFCP/PPy/NF electrolyzer delivers 10 mA cm −2 at 1.487 V and remains stable for 90 h at 100 mA cm −2 . DFT calculations reveal that interfacial electronic reconstruction lowers the reaction energy barriers, accounting for the enhanced catalytic activity and stability. • Two-step electrodeposition enables construction of the NFCP/PPy/NF catalyst. • PPy interlayer enhances adhesion, electron transfer, and catalyst stability. • Catalyst shows low overpotentials: 15.1 mV (HER) and 242.4 mV (OER) at 10 mA cm −2 . • Excellent durability in HER, OER, and overall water-splitting tests. • DFT reveals interfacial electronic reconstruction lowers reaction barriers.