1成果简介 

　　碳气凝胶因其轻质特性、可调导电性和结构多样性而被公认为极具前景的电磁波吸收材料，但由于阻抗失配和损耗机制单一，其性能受到限制。本文，扬州大学孙慧 教授、刘俊亮 教授等在《Carbon》期刊发表名为“Bimetal-modified multi-hierarchical carbon aerogels for high performance electromagnetic wave absorption: multi-phase coupling correlation and micro-morphologic multiple scattering strategies”的论文，研究提出了一种双金属协同策略，通过金属有机框架（MOF）衍生的自组装 followed by 热解，制备了CoNi/C复合气凝胶。

　　引入的CoNi多相体系不仅通过自然共振、交换共振和涡流效应优化了磁损耗，还调控了碳基体以增强导电网络和缺陷诱导极化。该CoNi/C气凝胶在2.7 mm波长下展现出-53.12 dB的卓越电磁波吸收性能，并在3.0 mm波长下具有8.32 GHz的有效吸收带宽。此外，该气凝胶还表现出优异的雷达隐身性能。本研究通过协调结构与电磁调控，为开发轻量化、高性能的微波吸收材料提供了新策略。

　　2图文导读  

　　图1. Illustration diagram of the synthesis for CoNi/C aerogel composite.

　　图2. (a) X-ray diffraction patterns, (b) Raman spectra, (c) Magnetic hysteresis loops and (d) N2 adsorption-desorption isotherms and (e) pore size distribution curves of Co/C aerogel, CoNi/C aerogel, and Ni/C aerogel. The XPS high-resolution spectra (f) C 1s, (g) Co 2p, (h) Ni 2p and (i) O 1s of CoNi/C aerogel.

　　图3. TEM images of Co/C aerogel (a), CoNi/C aerogel (b), and Ni/C aerogel (c); HR-TEM (d-e) and SAED (f) images of CoNi/C aerogel; STEM image of CoNi/C aerogel (g) and its corresponding EDX elemental mapping of C (h), Co (i), and Ni (j).

　　图4. (a) Permittivity real part, (b) imaginary part, (c) tangent (tan δε) of dielectric loss, (d) permeability real part, (e) imaginary part, (f) tangent (tan δμ) of magnetic loss of Co/C, CoNi/C and Ni/C aerogel.

　　图5.Co/C, CoNi/C and Ni/C aerogel: 3D (a-c) and 2D (d-f) color mapping of RL values at different thicknesses, (g-i) 2D |Zin/Z0| values at different thicknesses, (j-l) Frequency dependence of RL and |Zin/Z0|.

　　图6. Three-dimensional radar wave scattering signals and RCS radiation patterns at various plane wave angles (from 0° to 360°): (a) PEC, (b) Co/C aerogel, (c) CoNi/C aerogel, and (d) Ni/C aerogel; (e) schematic of the CST model; (f) 2D RCS simulation curves; (g) RCS reduction values for the samples.

　　图7. Schematic diagram of the EMW absorption mechanism in CoNi/C aerogel material.

　　3小结 

　　在本研究中，通过溶剂诱导的MOF自组装策略结合高温热解，成功制备了具有三维互连网络和均匀分散相的CoNi/C气凝胶复合材料。三维多孔结构的存在有效优化了阻抗匹配，并促进了电磁波的入射和多重散射。更重要的是，CoNi多相体系的引入构建了多重磁性网络，增强了磁损耗；同时，其丰富的异质界面与催化调控的碳基质（包括高导电性网络和可控缺陷）共同激发了强烈的界面极化、传导损耗和偶极极化，实现了介电损耗与磁损耗的协同效应。该设计在阻抗匹配与衰减能力之间实现了平衡，最终在2.7 mm厚度下获得-53.12 dB的最小反射损耗，并在3.0 mm厚度下实现8.32 GHz的超宽有效吸收带宽。本研究不仅为同时调控碳结构与电磁响应提供了设计策略，同时也为设计高性能轻质吸收材料开辟了新范式。

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