由于X射线吸收精细结构（X—rayabsorption fine structure，XAFS）可以原位探测吸收原子的2～3个邻近配位壳层，获得目标元素的电子结构信息和化学结构信息，所以XAFS已成为微观领域最重要的结构分析工具，丰富了我们对元素的重要化学...由于X射线吸收精细结构（X—rayabsorption fine structure，XAFS）可以原位探测吸收原子的2～3个邻近配位壳层，获得目标元素的电子结构信息和化学结构信息，所以XAFS已成为微观领域最重要的结构分析工具，丰富了我们对元素的重要化学性质和反应过程的认识。本文简述了XAFS的基本原理，探讨了样品制备、测试及数据分析等过程需关注的问题，重点综述了应用XAFS研究土壤重金属和营养元素的形态、土壤固一液界面的反应过程和机理，并指出其应用的局限性和未来发展的前景，旨在推动我国XAFS在土壤科学中的应用。由于土壤中界面反应的复杂性，XAFS应结合其他结构分析技术，结构分析技术应结合宏观数据和计算机模拟，土壤学应与其他学科交叉、融合，只有这样，才有可能在时间和空间尺度上阐明土壤组分在环境界面上的复杂反应过程和机理。展开更多
Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific c...Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific ca⁃pacity of MXene materials limit their further utilization.In this study,these issues are addressed using a heterostruc⁃ture strategy via a one-step selenization method to form Mo_(2)C@MoSe_(2).Synchrotron radiation X-ray spectroscopic and high-resolution transmission electron microscopy(HRTEM)characterizations revealed the heterostructure consisting of in-situ grown MoSe_(2)on Mo_(2)C MXene.Electrochemical tests proved the heterojunction electrode’s superior rate perfor⁃mance of 289.06 mAh·g^(-1)at a high current density of 5 A·g^(-1)and long cycling stability of 550 mAh·g^(-1)after 900 cycles at 1 A·g^(-1).This work highlights the useful X-ray spectroscopic analysis to directly elucidate the heterojunction structure,providing an effective reference method for probing heterostructures.展开更多
文摘由于X射线吸收精细结构（X—rayabsorption fine structure，XAFS）可以原位探测吸收原子的2～3个邻近配位壳层，获得目标元素的电子结构信息和化学结构信息，所以XAFS已成为微观领域最重要的结构分析工具，丰富了我们对元素的重要化学性质和反应过程的认识。本文简述了XAFS的基本原理，探讨了样品制备、测试及数据分析等过程需关注的问题，重点综述了应用XAFS研究土壤重金属和营养元素的形态、土壤固一液界面的反应过程和机理，并指出其应用的局限性和未来发展的前景，旨在推动我国XAFS在土壤科学中的应用。由于土壤中界面反应的复杂性，XAFS应结合其他结构分析技术，结构分析技术应结合宏观数据和计算机模拟，土壤学应与其他学科交叉、融合，只有这样，才有可能在时间和空间尺度上阐明土壤组分在环境界面上的复杂反应过程和机理。
基金supported by the National Natural Science Foundation of China(21373251)Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences,China(KZCX2-EW-307)~~
基金National Key Research and Development Program of China(2020YFA0405800)National Natural Science Foundation of China(12322515,U23A20121,12225508)+2 种基金Youth Innovation Promotion Association of CAS(2022457)National Postdoctoral Program for Innovative Talents(BX20230346)China Postdoctoral Science Foundation(2023M743365)。
文摘Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific ca⁃pacity of MXene materials limit their further utilization.In this study,these issues are addressed using a heterostruc⁃ture strategy via a one-step selenization method to form Mo_(2)C@MoSe_(2).Synchrotron radiation X-ray spectroscopic and high-resolution transmission electron microscopy(HRTEM)characterizations revealed the heterostructure consisting of in-situ grown MoSe_(2)on Mo_(2)C MXene.Electrochemical tests proved the heterojunction electrode’s superior rate perfor⁃mance of 289.06 mAh·g^(-1)at a high current density of 5 A·g^(-1)and long cycling stability of 550 mAh·g^(-1)after 900 cycles at 1 A·g^(-1).This work highlights the useful X-ray spectroscopic analysis to directly elucidate the heterojunction structure,providing an effective reference method for probing heterostructures.
