Defect-enriched multistage skeleton morphology Ni-Fe-P-Ni3S2 heterogeneous catalyst on Ni foam for efficient overall water splitting.

• A multistage morphology Ni-Fe-P-Ni 3 S 2 /NF heterogeneous electorcatalyst. • A simple synthesis method: electroless composite deposition. • A excellent electrocatalytic activity of HER and OER: 65 and 219 mV at 10 mA cm−2 in 1 M KOH. Exploring high-performance noble-metal-free bifunctional electrocatalysts is vitally crucial for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water electrolysis. Herein, the defect-enriched multistage morphology Ni-Fe-P-Ni 3 S 2 heterogeneous catalyst growth on the Ni Foam (Ni-Fe-P-Ni 3 S 2 /NF) is synthesized for the first time through electroless composite plating. Attributed to the heterogeneous structure between Ni-Fe-P alloys and Ni 3 S 2 , abundant lattice defects, exposed highly open multistage skeleton morphology, the optimal Ni-Fe-P-Ni 3 S 2 /NF catalyst only requires 65 and 219 mV to reach the current density of 10 mA cm−2 towards HER and OER in alkaline solution, respectively. With regard to the overall water splitting, the alkaline electrolyzer assembled by Ni-Fe-P-Ni 3 S 2 /NF electrodes exhibits a low cell voltage of 1.5 V at 10 mA cm−2. This research provides a new perspective for the preparation of heterogeneous catalysts between alloys and sulfides for overall water splitting. [ABSTRACT FROM AUTHOR]