Superelastic Au-decorated BNNR/graphene aerogels for synergistic infrared stealth and electromagnetic interference shielding

Boron nitride nanoribbon (BNNR) aerogels have garnered significant attention for their exceptional thermal stability and mechanical properties. However, their markedly increased thermal conductivity at high temperatures, high infrared emissivity, and insufficient dielectric loss severely limit their applications in infrared stealth and electromagnetic interference (EMI) shielding. Herein, a strategy is proposed to fabricate superelastic aerogels by chemical vapor deposition (CVD) of defective graphene (Gr) layers on BNNR skeletons, combined with ion sputtering to deposit Au nanoparticles (AuNPs). The Au-BN/Gr aerogel simultaneously achieves low thermal conductivity at high temperatures, low emissivity, and high electromagnetic loss. The thin CVD-grown Gr layers acts as junction nodes that endow the aerogel with extreme compressive deformability and as infrared opacifiers that effectively suppress high-temperature thermal radiation. Compared with the BNNR aerogel, its compressive strength at 80% strain increases by 353%, and its thermal conductivity at 300 °C decreases by 41.5% (down to 0.038 W m⁻¹ K⁻¹). Coupled with the low emissivity of the AuNPs, the aerogel exhibits a 240.3 °C thermal radiation temperature difference against a 300 °C background, revealing outstanding infrared stealth performance. Moreover, the three-dimensional conductive network rich in heterointerfaces constructed by Gr and AuNPs enhances electromagnetic loss, boosting the EMI shielding effectiveness (EMI SE) to 76.8 dB. Compared with similar materials, this aerogel exhibits superior and more comprehensive performance in thermal management, emissivity, and EMI shielding, highlighting its significant potential for applications in infrared stealth and electromagnetic shielding.