Facile Fabrication of Ultralight Magnetic Graphene/Hollow Microsphere Aerogels for High Performance Shielding of Electromagnetic Wave, Heat, and Sound

To address escalating concerns over electromagnetic, thermal, and acoustic pollution, this study proposes a scalable strategy for directly constructing ultralight (33.1 mg cm−3) multifunctional aerogels with a bilayer architecture. The aerogels are fabricated by integrating FeCo‐coated hollow microspheres (FeCo@HM) with reduced graphene oxide (rGO) networks. The resulting material exhibits exceptional performance in multiple aspects. For the 80 wt.% FeCo@HM composites, its specific electromagnetic shielding effectiveness (SSE) reaches 3931.5 dB cm2 g−1, with 74.8% of this effectiveness attributed to absorption. Additionally, it has an ultralow thermal conductivity of 0.037 W m−1 K−1 and superior sound absorption, with a noise reduction coefficient (NRC) of 0.62. The hierarchical porous architecture and magneto‐dielectric synergistic loss mechanism effectively prolong electromagnetic (EM) wave propagation paths and suppress secondary radiation. Additionally, the aerogel demonstrated robust Joule heating properties and infrared stealth capability. This work introduces a novel paradigm for next‐generation intelligent shielding materials, while its low‐cost, scalable fabrication process overcomes the manufacturing limitations of traditional aerogel production.