Design integration of hollow structures in graphene aerogel for multifunctional electromagnetic wave absorption applications

Abstract

The growing demand for high-performance electromagnetic wave-absorbing materials in intelligent driving, 5G communication, and harsh environment applications has driven the need for multifunctional solutions. This study introduces a novel route to fabricate a lightweight hollow glass microspheres (HGMs)/graphene composite aerogel with exceptional electromagnetic wave absorption, hydrophobicity, and thermal insulation. By using potassium hydroxide as a nontoxic reducing agent, we successfully integrated HGMs into a graphene aerogel matrix through a hydrothermal process followed by freeze-drying. The resulting composite exhibits uniformly dispersed HGMs, abundant heterogeneous interfaces, and optimized structural defects, which collectively enhance multiple reflections, dielectric loss, and impedance matching. The aerogel achieves a remarkable minimum reflection loss of −61.8 dB and an effective absorption bandwidth of 5.8 GHz at a thickness of only 1.9 mm. Furthermore, the material demonstrates excellent hydrophobicity and thermal insulation, making it highly suitable for demanding environments. This work not only offers a safe and efficient strategy for designing multifunctional electromagnetic wave-absorbing materials but also underscores their potential for applications in aerospace, telecommunications, and military systems. The study highlights the significance of green synthesis and structural engineering in advancing materials for next-generation electromagnetic wave absorption and thermal management.