Amorphous Ni(III)-based sulfides as bifunctional water and urea oxidation anode electrocatalysts for hydrogen generation from urea-containing water
Cui, Kai 1Wu, Xiaohong 1Qin, Wei 1Wu, Gang 2Jia, Xin 1Kang, Hongjun 1Yang, Xiaoxuan 2Li, Yunlong1
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作者信息
1. Harbin Inst Technol
2. SUNY Buffalo
折叠
Abstract
It is highly desired to design high-performance bifunctional electrocatalysts for an efficient oxygen evolution reaction (OER) and urea oxidation reaction (UOR) as anode water electrolysis reactions, which can be used for hydrogen production by using urea-containing water. Herein, a novel electrocatalyst composed of amorphous Ni (OH)S nanosheets was prepared by hydrolysis of NiCl2(CH3CSNH2)4 at room temperature. From spectroscopic characterization and density functional theory (DFT) calculations, the Ni(OH)S catalyst contains a Ni3+-rich phase, which can significantly accelerate the reaction kinetics. The anode electrocatalyst shows excellent OER activity, generating 10 mA cm-2 with only 250 mV overpotentials. When employed as a UOR anode, it could reach 10 mA cm-2 at 1.34 V, 140 mV lower than OER. Notably, the Ni(OH)S/NF anode exhibits decent bifunctional UOR and OER activities and presents the lowest overpotentials compared to a NiFe-PBA/NF UOR catalyst and a typical RuO2/NF OER catalyst. This work provides a novel strategy for synthesizing amorphous Ni (III)-based sulfides nanosheets for bifunctional OER/UOR electrocatalysts, which is significant for efficient and stable hydrogen production by using urea-containing wastewater.
NSTL
Elsevier