物理化学学报

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层级结构中界面电子转移与局域场增强的协同作用实现优异微波吸收

刘金坤1, 宋雨涵1, 李秉灿1, 付嘉瑜1, 傅奕杰1, 韩晓蕾1, 于元昊1, 郭子文2, 郑靖1, 侯旭1,2,3   

  1. 1 厦门大学化学化工学院, 固体表面物理化学国家重点实验室, 福建 厦门 361005;
    2 厦门大学人工智能研究所, 福建 厦门 361005;
    3 厦门大学材料学院, 福建 厦门 361005
  • 收稿日期:2026-06-12 修回日期:2026-07-29 录用日期:2026-08-12
  • 通讯作者: 郑靖 E-mail:zjing@xmu.edu.cn
  • 基金资助:
    本研究得到了国家自然科学基金(22275156, U25B20128, U24A20205, 52025132)、福建省自然科学基金(2026J002002)以及新基石科学基金会通过 XPLORERPRIZE 的支持。

Synergizing interfacial electron transfer and localized field enhancement in hierarchical structures for superior microwave absorption

Jinkun Liu1, Yuhan Song1, Bingcan Li1, Jiayu Fu1, Yijie Fu1, Xiaolei Han1, Yuanhao Yu1, Ziwen Guo2, Jing Zheng1, Xu Hou1,2,3   

  1. 1 State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, China;
    2 Institute of Artificial Intelligence, Xiamen University, Xiamen 361005, Fujian Province, China;
    3 College of Materials, Xiamen University, Xiamen 361005, Fujian Province, China
  • Received:2026-06-12 Revised:2026-07-29 Accepted:2026-08-12
  • Contact: Jing Zheng E-mail:zjing@xmu.edu.cn

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摘要： 为解决二维MXene材料的固有问题，特别是因过高金属导电性导致的阻抗失配以及纳米片的不利堆叠问题，本研究通过在球形SiO2模板上原位生长钴铁衍生碳纳米管，成功构建了具有多级异质结的分级结构。这种分级多维结构有效重构了MXene片层的空间排列，显著增加了有效接触面积，并促进了纵向电子传输。研究表明，MXene与CoFe-CNTs之间的强界面耦合引发了从Ti位点向C或N掺杂位点的显著界面电子转移。这种电荷密度的空间再分布实现了精确的界面电荷陷阱工程，在高频微波辐照下，通过载流子的持续捕获与释放，激发了强烈的界面极化和介电弛豫损耗。同时，碳纳米管的尖端效应及其与MXene形成的异质结引发了显著的局域场增强效应。这些局域强电场不仅加速了非弹性电子散射，还与CoFe纳米颗粒的磁损耗表现出显著的协同效应。因此，通过梯度阻抗调控与多级耗散机制的协同作用，该复合材料在1.25 mm超薄厚度下实现了5.2 GHz的宽吸收带宽，在1.95 mm厚度下达到了-60.37 dB的优异反射损耗。本研究通过调控界面电荷动力学，为高能量耗散、高效微波吸收体的设计提供了全新的物理范式。

关键词: 层级结构, 界面电荷陷阱, 局域电场增强, 电磁波吸收

Abstract: To mitigate the intrinsic challenges of 2D MXene, specifically impedance mismatch arising from excessive metallic conductivity and the detrimental restacking of nanosheets, this work demonstrates the successful construction of hierarchical architectures featuring multistage heterojunctions via the in situ growth of CoFe-derived carbon nanotubes (CNTs) on spherical SiO2 templates. This hierarchical, multidimensional structure effectively reorganizes the spatial arrangement of MXene sheets, significantly increases the effective contact area, and promotes longitudinal electron transport. Our investigations reveal that the strong interfacial coupling between MXene and CoFe-CNTs triggers significant interfacial electron transfer from Ti sites toward C or N-doped sites. This spatial redistribution of charge density enables precise interface charge trap engineering, which, under high-frequency microwave irradiation, induces vigorous interfacial polarization and dielectric relaxation loss through the continuous capture and release of carriers. Simultaneously, the tip effects of the CNTs and their heterogeneous junctions with MXene provoke profound localized field enhancement. These intense localized electric fields not only accelerate inelastic electron scattering but also exhibit a pronounced synergistic effect with the magnetic loss of CoFe nanoparticles. Consequently, through the synergy of gradient impedance regulation and multistage dissipation mechanisms, the composite achieves a broad absorption bandwidth of 5.2 GHz at an ultrathin thickness of 1.25 mm, and an exceptional reflection loss of −60.37 dB at a thickness of 1.95 mm. By modulating interfacial charge dynamics, this research offers a novel physical paradigm for the design of high-efficiency microwave absorbers with elevated energy dissipation rates.

Key words: Hierarchical structure, Interfacial charge traps, Localized electric-field enhancement, Electromagnetic wave absorption