{"title":"ZIF-derived N-doped carbon nanorods supporting bimetallic CoFe single-atoms/nanoclusters as bifunctional oxygen electrocatalysts for stable Zn-air batteries","authors":"Hong-Shuang Fan, Fei-Xiang Ma, Zi-Hao Liu, Wen-Hui Wang, Zheng-Qi Liu, Xiong-Yi Liang, Yue Du, Yang-Yang Li, Liang Zhen, Cheng-Yan Xu","doi":"10.1007/s12598-024-02676-y","DOIUrl":null,"url":null,"abstract":"<p>High-performance bifunctional oxygen electrocatalysts that simultaneously boost the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) need to be developed for advanced rechargeable Zn-air battery applications. In this work, a zeolitic imidazolate framework (ZIF)-phase conversion associated with a subsequent thermal fixing strategy was developed to fabricate bimetallic CoFe single atoms/clusters embedded in N-doped carbon (denoted as CoFe–N–C) nanorods, which can serve as efficient bifunctional ORR/OER electrocatalysts. Microstructural observation and X-ray absorption spectroscopy analysis confirm the co-existence of highly active Co/Fe–N<sub><i>x</i></sub> dual sites and CoFe alloy nanoclusters. X-ray photoelectron spectroscopy (XPS) results prove that implanting secondary Fe atoms into Co–N–C matrix nanorods can induce electronic redistribution of atomic Co/Fe active sites and generate synergistic effects, which would optimize the adsorption energy of the reaction intermediates and thus enhance the bifunctional ORR/OER activity. The bimetallic CoFe–N–C nanorods exhibit significantly enhanced bifunctional ORR/OER activity and stability than the monometallic Co/Fe–N–C nanorods in alkaline electrolytes in terms of a very positive half-wave potential of 0.90 V (vs. reversible hydrogen electrode (RHE)) for ORR, and an overpotential of 440 mV to reach current density of 10 mA·cm<sup>−2</sup> for OER, yielding a small overpotential gap of 0.77 V. Furthermore, the rechargeable Zn-air batteries using bimetallic CoFe–N–C nanorods as air–cathode catalyst demonstrates peak power density of 200.7 mW·cm<sup>−2</sup> and robust cycling stability of up to 200 h, corresponding to 1200 discharge–charge cycles.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\n","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":null,"pages":null},"PeriodicalIF":9.6000,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rare Metals","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1007/s12598-024-02676-y","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
High-performance bifunctional oxygen electrocatalysts that simultaneously boost the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) need to be developed for advanced rechargeable Zn-air battery applications. In this work, a zeolitic imidazolate framework (ZIF)-phase conversion associated with a subsequent thermal fixing strategy was developed to fabricate bimetallic CoFe single atoms/clusters embedded in N-doped carbon (denoted as CoFe–N–C) nanorods, which can serve as efficient bifunctional ORR/OER electrocatalysts. Microstructural observation and X-ray absorption spectroscopy analysis confirm the co-existence of highly active Co/Fe–Nx dual sites and CoFe alloy nanoclusters. X-ray photoelectron spectroscopy (XPS) results prove that implanting secondary Fe atoms into Co–N–C matrix nanorods can induce electronic redistribution of atomic Co/Fe active sites and generate synergistic effects, which would optimize the adsorption energy of the reaction intermediates and thus enhance the bifunctional ORR/OER activity. The bimetallic CoFe–N–C nanorods exhibit significantly enhanced bifunctional ORR/OER activity and stability than the monometallic Co/Fe–N–C nanorods in alkaline electrolytes in terms of a very positive half-wave potential of 0.90 V (vs. reversible hydrogen electrode (RHE)) for ORR, and an overpotential of 440 mV to reach current density of 10 mA·cm−2 for OER, yielding a small overpotential gap of 0.77 V. Furthermore, the rechargeable Zn-air batteries using bimetallic CoFe–N–C nanorods as air–cathode catalyst demonstrates peak power density of 200.7 mW·cm−2 and robust cycling stability of up to 200 h, corresponding to 1200 discharge–charge cycles.
期刊介绍:
Rare Metals is a monthly peer-reviewed journal published by the Nonferrous Metals Society of China. It serves as a platform for engineers and scientists to communicate and disseminate original research articles in the field of rare metals. The journal focuses on a wide range of topics including metallurgy, processing, and determination of rare metals. Additionally, it showcases the application of rare metals in advanced materials such as superconductors, semiconductors, composites, and ceramics.