Bimetallic Nickel Cobalt Sulfide as Efficient Electrocatalyst for Zn–Air Battery and Water Splitting

Nano-Micro Letters

Wen Xiao¹  John Wang¹  Daqiang Gao²  Tongtong Wang²  Jingyan Zhang²  Pinxian Xi³  Jinlan Wang⁴  Xiaowan Bai⁴ 

[1] Department of Material Science and Engineering, National University of Singapore;Key Laboratory for Magnetism and Magnetic Materials of MOE, Key Laboratory of Special Function Materials and Structure Design of MOE, Lanzhou University;Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and The Research Center of Biomedical Nanotechnology, Lanzhou University;School of Physics, Southeast University;

关键词: (Ni,Co)S2 nanosheet arrays;    DFT calculations;    Zn–air batteries;    Water splitting;   

DOI  :  10.1007/s40820-018-0232-2

来源: DOAJ

【 摘 要 】

Abstract The development of efficient earth-abundant electrocatalysts for oxygen reduction, oxygen evolution, and hydrogen evolution reactions (ORR, OER, and HER) is important for future energy conversion and energy storage devices, for which both rechargeable Zn–air batteries and water splitting have raised great expectations. Herein, we report a single-phase bimetallic nickel cobalt sulfide ((Ni,Co)S2) as an efficient electrocatalyst for both OER and ORR. Owing to the synergistic combination of Ni and Co, the (Ni,Co)S2 exhibits superior electrocatalytic performance for ORR, OER, and HER in an alkaline electrolyte, and the first principle calculation results indicate that the reaction of an adsorbed O atom with a H2O molecule to form a *OOH is the potential limiting step in the OER. Importantly, it could be utilized as an advanced air electrode material in Zn–air batteries, which shows an enhanced charge–discharge performance (charging voltage of 1.71 V and discharge voltage of 1.26 V at 2 mA cm−2), large specific capacity (842 mAh gZn−1 at 5 mA cm−2), and excellent cycling stability (480 h). Interestingly, the (Ni,Co)S2-based Zn–air battery can efficiently power an electrochemical water-splitting unit with (Ni,Co)S2 serving as both the electrodes. This reveals that the prepared (Ni,Co)S2 has promising applications in future energy conversion and energy storage devices.

【 授权许可】

Unknown