2D transition metal carbide/nitride (MXene) nanomaterials have prospective applications in high-performance microwave absorption (MA). However, the excessively high permittivity, absence of magnetic loss, and susceptible oxidizability of MXene severely hinder the enhancement of its MA properties. Here, we used a facile organic solution–phase thermal decomposition method to prepare dielectric–magnetic MXene@CoNi nanocomposites with heterojunctions, which can effectively prevent the oxidation of MXene. Subsequently, the MXene@CoNi nanocomposites were integrated with magnetic CoNi alloys, MXene microspheres (MXene MPs), and a silicon rubber (SR) matrix to construct multilayered CoNi/MXene@CoNi/MXene MPs/SR composites by casting and curing. Benefiting from the multilayered structure and complementary effects of the dielectric and magnetic components, the multilayered CoNi/MXene@CoNi/MXene MPs/SR composites composed of matching, absorbing, and reflective layers showed a remarkable minimum reflection loss of −53.3 dB and an ultra-broad effective absorption bandwidth up to 11.12 GHz at a thickness of 2.96 mm. These results demonstrated the developed multilayered composites are promising candidates for high-performance MA. Our study provides new insights into the development of ultra-broadband MXene-based absorbent materials.

中文翻译：

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CoNi/MXene@CoNi/MXene微球/硅橡胶多层复合材料用于超宽带微波吸收

二维过渡金属碳化物/氮化物（MXene）纳米材料在高性能微波吸收（MA）方面具有广阔的应用前景。然而，MXene过高的介电常数、缺乏磁损耗和易氧化性严重阻碍了其MA性能的增强。在这里，我们采用一种简便的有机溶液相热分解方法制备了具有异质结的介电磁性MXene@CoNi纳米复合材料，可以有效防止MXene的氧化。随后，将MXene@CoNi纳米复合材料与磁性CoNi合金、MXene微球（MXene MPs）和硅橡胶（SR）基体集成，通过浇铸和固化构建多层CoNi/MXene@CoNi/MXene MPs/SR复合材料。受益于多层结构以及介电和磁性成分的互补效应，由匹配层、吸收层和反射层组成的多层CoNi/MXene@CoNi/MXene MPs/SR复合材料表现出显着的最小反射损耗为-53.3 dB和超强反射损耗。 -厚度为 2.96 毫米时，有效吸收带宽高达 11.12 GHz。这些结果表明，所开发的多层复合材料是高性能 MA 的有希望的候选者。我们的研究为超宽带 MXene 基吸收材料的开发提供了新的见解。