{"title":"WO2–N co-doped 2D Carbon nanosheets as multifunctional additives for enhancing the electrochemical hydrogen storage performance of Co2B","authors":"","doi":"10.1016/j.ijhydene.2024.09.126","DOIUrl":null,"url":null,"abstract":"<div><p>Co<sub>2</sub>B, with its high theoretical hydrogen storage capacity, is a potential solid-state hydrogen storage material. However, its poor cycling life limits its practical application. In this work, in order to improve the cycling stability and reversibility of hydrogen absorption and desorption of Co<sub>2</sub>B, we propose to use WO<sub>2</sub>–N–C nanosheets as dopants to mix with Co<sub>2</sub>B, thereby enhancing its practical performance. Two-dimensional tungsten oxide-nitrogen-carbon (WO<sub>2</sub>–N–C) nanosheets was syntheized via a liquid-phase approach, using a tungstenate-polydopamine precursor followed by thermal treatment. Subsequently, these WO<sub>2</sub>–N–C nanosheets were compounded with cobalt boride (Co<sub>2</sub>B) particles through ball milling at various ratios of 1%, 3%, and 5%, which were confirmed by XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) methods. Employing a comprehensive suite of electrochemical analyses, including corrosion potential measurements, polarization curves, step voltammetry, and electrochemical impedance spectroscopy (EIS), we found that the incorporation of WO<sub>2</sub>–N–C significantly enhances the corrosion resistance and electrochemical activity of Co<sub>2</sub>B. Furthermore, cyclic life tests revealed that the WO<sub>2</sub>–N–C-doped Co<sub>2</sub>B composites exhibit superior discharge capacities and capacity retention rates compared to pristine Co<sub>2</sub>B. Notably, the 3% WO<sub>2</sub>–N–C-doped Co<sub>2</sub>B composite demonstrated the optimal electrochemical performance, achieving a maximum discharge specific capacity of 555 mAh g<sup>−1</sup> and maintaining 82% of its initial capacity after 50 cycles. Our findings underscore the dual role of WO<sub>2</sub>–N–C in not only augmenting the surface electrochemical activity of Co<sub>2</sub>B but also providing a protective surface layer, thereby enhancing its overall electrochemical performance.</p></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":null,"pages":null},"PeriodicalIF":8.1000,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Hydrogen Energy","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0360319924038357","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Co2B, with its high theoretical hydrogen storage capacity, is a potential solid-state hydrogen storage material. However, its poor cycling life limits its practical application. In this work, in order to improve the cycling stability and reversibility of hydrogen absorption and desorption of Co2B, we propose to use WO2–N–C nanosheets as dopants to mix with Co2B, thereby enhancing its practical performance. Two-dimensional tungsten oxide-nitrogen-carbon (WO2–N–C) nanosheets was syntheized via a liquid-phase approach, using a tungstenate-polydopamine precursor followed by thermal treatment. Subsequently, these WO2–N–C nanosheets were compounded with cobalt boride (Co2B) particles through ball milling at various ratios of 1%, 3%, and 5%, which were confirmed by XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) methods. Employing a comprehensive suite of electrochemical analyses, including corrosion potential measurements, polarization curves, step voltammetry, and electrochemical impedance spectroscopy (EIS), we found that the incorporation of WO2–N–C significantly enhances the corrosion resistance and electrochemical activity of Co2B. Furthermore, cyclic life tests revealed that the WO2–N–C-doped Co2B composites exhibit superior discharge capacities and capacity retention rates compared to pristine Co2B. Notably, the 3% WO2–N–C-doped Co2B composite demonstrated the optimal electrochemical performance, achieving a maximum discharge specific capacity of 555 mAh g−1 and maintaining 82% of its initial capacity after 50 cycles. Our findings underscore the dual role of WO2–N–C in not only augmenting the surface electrochemical activity of Co2B but also providing a protective surface layer, thereby enhancing its overall electrochemical performance.
期刊介绍:
The objective of the International Journal of Hydrogen Energy is to facilitate the exchange of new ideas, technological advancements, and research findings in the field of Hydrogen Energy among scientists and engineers worldwide. This journal showcases original research, both analytical and experimental, covering various aspects of Hydrogen Energy. These include production, storage, transmission, utilization, enabling technologies, environmental impact, economic considerations, and global perspectives on hydrogen and its carriers such as NH3, CH4, alcohols, etc.
The utilization aspect encompasses various methods such as thermochemical (combustion), photochemical, electrochemical (fuel cells), and nuclear conversion of hydrogen, hydrogen isotopes, and hydrogen carriers into thermal, mechanical, and electrical energies. The applications of these energies can be found in transportation (including aerospace), industrial, commercial, and residential sectors.