Zihan Li⁺, Kaihang Wang⁺, Xiao Tan, Xin Liu, Guixue Wang, Guangwen Xie*, Luhua Jiang**

College of Materials Science and Engineering, Qingdao University of Science and

Technology, Qingdao, 266042, P.R. China

⁺Zihan Li and Kaihang Wang contribute equally to this work.

*Corresponding authors:

Guangwen Xie, *E-mail: xiegw@qust.edu.cn; Luhua Jiang, *E-mail: luhuajiang@qust.edu.cn

Abstract

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- Ni₃S₂ heterogeneous catalyst growth on the Ni Foam (Ni-Fe-P-Ni₃S₂/NF) is synthesized for the first time through electroless composite plating. Attributed to the heterogeneous structure between Ni-Fe-P alloys and Ni₃S₂, abundant lattice defects, exposed highly open multistage skeleton morphology, the optimal Ni-Fe-P-Ni₃S₂/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- Ni₃S₂/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.

Keywords: Ni-Fe-P alloys; Ni₃S₂; heterogeneous electrocatalyst; water splitting; electroless composite deposition

https://doi.org/10.1016/j.cej.2021.130390