Double-layer absorbers have recently been extensively studied because single-layer absorbers can hardly meet the requirements of advanced absorbing materials. However, determining how to couple the matching and absorption layers remains a challenge. In the present work, we applied the hydrothermal method to prepare an ultrasmall Fe3O4 nanoparticle and a hierarchical MXene/Fe3O4 composite and then studied the microwave attenuation capabilities of single- and double-layer absorbers containing these two materials with different thicknesses. Absorbers with well-coupled layers showed improved absorption performance on account of the excellent impedance matching behavior of the Fe3O4 layer and the high microwave attenuation capability of the MXene/Fe3O4 layer. When the thickness of the matching layer filled with Fe3O4 was 0.1 mm and that of the absorption layer filled with MXene/Fe3O4 was 1.9 mm, a maximum reflection loss of −48.7 dB was achieved at 9.9 GHz. More importantly, when the thicknesses of the matching and absorption layers were 0.9 and 1.1 mm, respectively, the effective bandwidth was nearly 3.9 GHz. The double-layer absorbers with enhanced absorption properties may be regarded as a new generation of materials for electromagnetic wave absorption.

中文翻译：

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基于分层 MXene 复合材料的双层吸收体通过优化组合实现微波吸收

由于单层吸波材料难以满足先进吸波材料的要求，近年来双层吸波材料被广泛研究。然而，确定如何耦合匹配层和吸收层仍然是一个挑战。在目前的工作中，我们应用水热法制备了超小 Fe3O4 纳米颗粒和分层 MXene/Fe3O4 复合材料，然后研究了包含这两种不同厚度材料的单层和双层吸收体的微波衰减能力。由于 Fe3O4 层的出色阻抗匹配行为和 MXene/Fe3O4 层的高微波衰减能力，具有良好耦合层的吸收器显示出改善的吸收性能。当填充 Fe3O4 的匹配层厚度为 0. 1 mm，填充有 MXene/Fe3O4 的吸收层为 1.9 mm，在 9.9 GHz 下实现了 -48.7 dB 的最大反射损耗。更重要的是，当匹配层和吸收层的厚度分别为 0.9 和 1.1 mm 时，有效带宽接近 3.9 GHz。具有增强吸收性能的双层吸收体可被视为新一代电磁波吸收材料。