In situ fabrication of Ni 3 S 2 /Cu 2 S heterojunction on nickel foam as a highly efficient and durable electrocatalyst for overall water splitting

• Published in: Journal of colloid and interface science 2024-09, Vol.678 (Pt C), p.804
• Main Authors: Zhang, Siqi, Yao, Huiqin, Deng, Ruxin, Zhan, Jiayi, Tong, Tian, Wang, Yixuan, Yan, Haiqing, Wang, Chaonan, Li, Cheng, Dong, Hongliang, Ma, Shulan
• Format: Article
• Language: English
• ISSN: 1095-7103

The development of cost-efficient bifunctional electrocatalysts is significant for overall water splitting. Herein, we report the in situ fabrication of heterogeneous NF/Ni S /Cu S-X (where X refers to Cu concentrations of 50, 75, and 100 mM) on nickel foam (NF) using an electrodeposition-hydrothermal method. The in situ electrodeposited metallic Cu layers on the NF conferred higher stability to the resulting bimetallic sulfide of Ni S /Cu S. In alkaline media (1 M KOH), the optimized NF/Ni S /Cu S-75 exhibited ultra-low overpotentials of 108 and 166 mV during the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA·cm . For overall water splitting, the catalyst showed a significantly low cell voltage of 1.50 V and long stabilization time (≥150h)at15mA·cm . Density functional theory calculations revealed that the formation of Ni S /Cu S heterojunction reduced the Gibbs free energy of hydrogen adsorption (ΔG ) on the S site, thus facilitating H generation. This study serves as a guide for tailoring transition metal-based catalysts with enhanced activity and long-term durability, thereby contributing to highly efficient water electrolysis for large-scale hydrogen production.