{"title":"Introducing sulfur to nickel-iron selenide for high-efficiency alkaline seawater electrolysis","authors":"Xuanwa Chen, Yanhui Yu, Xingqi Han, Huan Wang, Yingjie Hua, Daoxiong Wu, Peilin Deng, Juanxiu Xiao, Xinlong Tian, Jing Li","doi":"10.1007/s11426-023-1965-y","DOIUrl":null,"url":null,"abstract":"<p>Seawater electrolysis is an effective way to obtain hydrogen (H<sub>2</sub>) in a sustainable manner. However, the lack of electrocatalysts with high activity, stability, and selectivity for oxygen evolution reaction (OER) severely hinders the development of seawater electrolysis technology. Herein, sulfur-doped nickel-iron selenide nanosheets (S-NiFeSe<sub>2</sub>) were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater electrolysis. The overpotential is 367 mV, and it can run stably for over 50 h at 100 mA cm<sup>−2</sup>. Excitingly, the S-NiFeSe<sub>2</sub>∥Pt/C pair exhibits cell voltage of 1.54 V at 10 mA cm<sup>−2</sup> under alkaline seawater conditions, which can run smoothly for 100 h without decay, and the efficiency of electricity-to-hydrogen (ETH) energy conversion reaches more than 80%. Such electrode, with abundant accessible reactive sites and good corrosion resistance, is a good candidate for seawater electrolysis. Moreover, density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER, and the step of *OH → *O is the potential rate-limiting step. In this work, the true reactive site in nickel-iron selenides is the Ni sites, but not the Fe sites as commonly believed.</p>","PeriodicalId":772,"journal":{"name":"Science China Chemistry","volume":null,"pages":null},"PeriodicalIF":10.4000,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Science China Chemistry","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1007/s11426-023-1965-y","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Seawater electrolysis is an effective way to obtain hydrogen (H2) in a sustainable manner. However, the lack of electrocatalysts with high activity, stability, and selectivity for oxygen evolution reaction (OER) severely hinders the development of seawater electrolysis technology. Herein, sulfur-doped nickel-iron selenide nanosheets (S-NiFeSe2) were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater electrolysis. The overpotential is 367 mV, and it can run stably for over 50 h at 100 mA cm−2. Excitingly, the S-NiFeSe2∥Pt/C pair exhibits cell voltage of 1.54 V at 10 mA cm−2 under alkaline seawater conditions, which can run smoothly for 100 h without decay, and the efficiency of electricity-to-hydrogen (ETH) energy conversion reaches more than 80%. Such electrode, with abundant accessible reactive sites and good corrosion resistance, is a good candidate for seawater electrolysis. Moreover, density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER, and the step of *OH → *O is the potential rate-limiting step. In this work, the true reactive site in nickel-iron selenides is the Ni sites, but not the Fe sites as commonly believed.
期刊介绍:
Science China Chemistry, co-sponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China and published by Science China Press, publishes high-quality original research in both basic and applied chemistry. Indexed by Science Citation Index, it is a premier academic journal in the field.
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