基于石墨烯气凝胶FeCoSe@MoS₂异质结构，用于电磁防护-红外隐身

1成果简介

开发轻质、高效且可调谐的电磁波（EMW）吸收材料，对于减轻电磁污染至关重要。然而，传统的粉末状吸收材料通常存在不可持续性和功能受限的问题。本文，西安理工大学任鹏刚 教授团队在《ACS Appl. Mater. Interfaces》期刊发表名为“Heterostructures of FeCoSe@MoS2on Reduced Graphene Oxide Aerogels for Electromagnetic Wave Absorption at Low Frequency and Thermal Insulation”的论文，研究通过溶剂热法结合后续定向冷冻干燥策略，将FeCoSe@MoS₂与GO整合，成功制备了具有多尺度异质结构的FeCoSe@MoS₂/还原石墨烯氧化物（rGO）气凝胶。合理多组分配比所形成的互连多孔结构及丰富的异质界面，有助于优化阻抗匹配并丰富电磁波损耗行为。通过调整组分配比，可有效调控电磁波吸收性能。

经组分优化后的FeCoSe@MoS₂/rGO气凝胶实现了−55.21 dB的最小反射损耗（RLmin）以及6.74 GHz（11.26−18.0 GHz）的出色有效吸收带宽（EAB）。值得注意的是，所得气凝胶表现出显著的低频电磁波响应。在C波段，当匹配厚度为4.09 mm时，7.24 GHz处的最小反射损耗（RLmin）为−43.83 dB；当匹配厚度为4.55 mm时，有效吸收带宽（EAB）可达2.63 GHz（5.31−7.94 GHz）。通过调整匹配厚度，低频电磁波带宽可达3.04 GHz（4.96−8 GHz）。通过灵活调节匹配厚度，所得气凝胶的电磁波带宽可达13.04 GHz，几乎完全覆盖C、X和Ku波段。雷达截面模拟直观验证了所得气凝胶作为先进隐身材料的有效性。此外，所制备的气凝胶还展现出卓越的隔热性能，满足了多功能应用的要求。本研究通过结构设计和组分优化，为构建多功能电磁波吸收气凝胶提供了创新性见解。

2图文导读

Figure 1.(a) Schematic diagram of the fabrication procedures for the FeCoSe@MoS2/rGO aerogel. (b−d) Versatility of the resultant FeCoSe@MoS2/rGO aerogel.

Figure 2.(a) XRD patterns, (b) FTIR spectra, (c) Raman spectra, and (d) XPS spectra of the prepared specimens. High-resolution XPS spectra for (e) Fe 2p, (f) Co 2p, (g) Se 3d, (h) Mo 3d, and (i) C 1s.

Figure 3.(a−c) Surface and (e−g) cross-sectional SEM images of FCSMR aerogel. (d, h) EDS elemental maps of FCSMR aerogel.

Figure 4.(a) Real parts and (b) imaginary parts of permittivity. (c) Dielectric loss tangent. (d) Real parts and (e) imaginary parts of permeability. (f) Magnetic loss tangent. Three-dimensional Cole-Cole curves of (g) the rGO aerogel, (h) the FCMR aerogel, (i) the MR aerogel, (j) the FCSR aerogel, and (k) the FCSMR aerogel. (l) C0plots of the resultant aerogels.

Figure 5.The 2D reflection loss plots, 3D reflection loss diagrams, and 2D reflection loss mapping curves of (a1−a3) rGO aerogel, (b1−b3) FCMR aerogel, (c1−c3) MR aerogel, (d1−d3) FCSR aerogel, and (e1−e3) FCSMR aerogel.

Figure 6.Zvalues of (a) rGO aerogel, (b) FCMR aerogel, (c) MR aerogel, (d) FCSR aerogel, and (e) FCSMR aerogel. (f) Attenuation constant. (g) RL of FCSMR aerogel at λ/4 matching thickness (tm) versus matching frequency (fm).

Figure 7.3D and 2D reflection loss diagrams of (a1−a3) FSCMR-1 aerogel, (b1−b3) FSCMR-2 aerogel, (c1−c3) FSCMR-3 aerogel, (d1−d3) FSCMR-4 aerogel, and (e1−e3) FSCMR-5 aerogel. Impedance matching maps of (a4) FCSMR-1 aerogel, (b4) FCSMR-2 aerogel, (c4) FCSMR-3 aerogel, (d4) FCSMR-4 aerogel, and (e4) FCSMR-5 aerogel.

Figure 8.a) Schematic illustration of the EMW absorption mechanism for the FCSMR aerogel. (b) RCS simulation model. (c1−c6) 3D RCS diagrams. (d, e) 2D RCS values and (f) RCS reduction values of PEC and PEC coated with various absorbers.

Figure9.(a) Schematic illustration of the heat-transfer mechanism in the FCSMR aerogel. (b, c) Infrared thermal images of the FCSMR aerogel: (b) top view and (c) side view. (d) Surface temperature evolution of the aerogel as a function of time under different heating sources. (e) Temperature profiles of the upper and bottom surfaces during heating. (f) Temperature difference between the top and bottom surfaces. (g) Digital photographs demonstrating the thermal insulation performance of the FCSMR aerogel.

3小结

总而言之，通过一种简便的溶剂热法结合冻干策略，成功制备了由FeCoSe@MoS₂修饰的基于rGO的气凝胶。所得气凝胶呈现分级多孔结构，这有助于改善阻抗匹配，并促进残留电磁波在孔壁上的多次反射。此外，引入FeCoSe@MoS₂既能有效抑制原始rGO气凝胶的高电导率，又能形成大量异质界面。电导率的降低可进一步优化阻抗匹配，而异质界面的形成则丰富了电磁波的衰减机制。这些优势共同使所得气凝胶实现了卓越的电磁波吸收性能。该FCSMR气凝胶在13.45 GHz时展现出−55.21 dB的最佳最小反射系数（RLmin），匹配厚度为2.40 mm，且具有6.74 GHz（11.26−18.0 GHz）的宽带有效吸收带宽（EAB）。此外，通过调节匹配厚度，其有效吸收带（EAB）可扩展至几乎覆盖整个 4.96–18.0 GHz 的测量频率范围。更重要的是，所得的 FCSMR 气凝胶在低频电磁波响应方面表现卓越。在 4.09 mm 的匹配厚度下，其在 7.24 GHz（C 波段）处获得了 −43.83 dB 的优异 RLmin 值，并具有 2.63 GHz（5.31−7.94 GHz）的宽 EAB。此外，由于存在多孔结构，热传导被显著抑制，这赋予了所制备的FCSMR气凝胶卓越的隔热性能。本研究通过组件优化和结构设计，为制造用于极端环境应用的电磁防护-红外隐身多功能集成气凝胶提供了新的见解。

文献：
https://doi.org/10.1021/acsami.6c09650

来源：材料分析与应用1