Through inserting SiO₂@Au into the reduced graphene oxide (rGO) layers, the rGO-SiO₂@Au composites were prepared via the vacuum-assisted electrostatic self-assembly method. The obtained composites exhibit excellent electromagnetic interference (EMI) shielding effectiveness due to the successful construction of multi-nanocavities (spherical SiO₂ cavities and layered air cavities between rGO), multi-reflection interfaces (rGO and Au shell) and continuous conductive network (rGO-Au-rGO). Among them, the total shielding effectiveness (SET) of the composites with 75.78 wt% SiO₂ and 19.38 wt% rGO can reach 38.4 dB at 18 GHz. Thereinto, the shielding effectiveness absorption (SEA) is 36.4 dB, 1.3 and 13.5 times higher than that of rGO and SiO₂@Au. And the shielding effectiveness reflection (SER) is always below 5 dB from 1 to 18 GHz, much lower than that of rGO (about 15 dB). Further studies found that the SEA values were enhanced at 12.6 GHz and 6.2 GHz due to the construction of cavities and location of Au nanoparticles between the rGO layers. This study provides a simple and mild method to prepare high-performance thin-layered materials with applications in the field of EMI absorption shielding.

通过将SiO ₂ @Au插入还原氧化石墨烯（rGO）层中，通过真空辅助静电自组装方法制备了rGO -SiO ₂ @Au复合材料。由于成功地构建了多纳米腔（球形SiO ₂腔和rGO之间的分层气腔），多反射界面（rGO和Au壳）和连续导电网络（rGO），所获得的复合材料具有出色的电磁干扰（EMI）屏蔽效果。-Au-rGO）。其中，具有75.78 wt％SiO ₂的复合材料的总屏蔽效果（SET）和19.38 wt％的rGO在18 GHz时可以达到38.4 dB。其中，屏蔽效率吸收（SEA）是rGO和SiO ₂ @Au的36.4 dB，1.3和13.5倍。在1至18 GHz范围内，屏蔽效率反射（SER）始终低于5 dB，远低于rGO（约15 dB）。进一步的研究发现，由于腔的构造以及rGO层之间的Au纳米颗粒的位置，SEA值在12.6 GHz和6.2 GHz时有所提高。这项研究提供了一种简单而温和的方法来制备高性能薄层材料，并将其应用于EMI吸收屏蔽领域。