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Nano Research

Article Title

Heterogeneous lamellar-edged Fe-Ni(OH)2/Ni3S2 nanoarray for efficient and stable seawater oxidation

Authors

Baihua Cui, School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China;Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350207, China;School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Zheng Hu, School of Science, Tianjin University, Tianjin 300072, China
Chang Liu, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Siliang Liu, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Fangshuai Chen, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Shi Hu, School of Science, Tianjin University, Tianjin 300072, China
Jinfeng Zhang, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Wei Zhou, School of Science, Tianjin University, Tianjin 300072, China
Yida Deng, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Zhenbo Qin, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Zhong Wu, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Yanan Chen, School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China
Lifeng Cui, School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China
Wenbin Hu, Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350207, China;School of Materials Science and Engineering, Tianjin University, Tianjin 300372, China

Keywords

lamellar edges, Fe-Ni(OH)2/Ni3S2, seawater oxidation, chlorine electrochemistry, electrocatalysis

Abstract

Development of efficient non-precious catalysts for seawater electrolysis is of great significance but challenging due to the sluggish kinetics of oxygen evolution reaction (OER) and the impairment of chlorine electrochemistry at anode. Herein, we report a heterostructure of Ni3S2 nanoarray with secondary Fe-Ni(OH)2 lamellar edges that exposes abundant active sites towards seawater oxidation. The resultant Fe-Ni(OH)2/Ni3S2 nanoarray works directly as a free-standing anodic electrode in alkaline artificial seawater. It only requires an overpotential of 269 mV to afford a current density of 10 mA·cm−2 and the Tafel slope is as low as 46 mV·dec−1. The 27-hour chronopotentiometry operated at high current density of 100 mA·cm−2 shows negligible deterioration, suggesting good stability of the Fe-Ni(OH)2/Ni3S2@NF electrode. Faraday efficiency for oxygen evolution is up to ~ 95%, revealing decent selectivity of the catalyst in saline water. Such desirable catalytic performance could be benefitted from the introduction of Fe activator and the heterostructure that offers massive active and selective sites. The density functional theory (DFT) calculations indicate that the OER has lower theoretical overpotential than Cl2 evolution reaction in Fe sites, which is contrary to that of Ni sites. The experimental and theoretical study provides a strong support for the rational design of high-performance Fe-based electrodes for industrial seawater electrolysis.

Publisher

Tsinghua University Press

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