Protective Carbon Aerogels Derived from Leather Solid Waste for High Electromagnetic Interference Shielding and Efficient Thermal Management

Owing to their remarkable lightweight, high specific surface area, and porous properties, carbon aerogels ascend to crucial candidates for multifunctional protection. Nevertheless, formidable challenges persist in carbon-based aerogels with a robust electromagnetic attenuation capacity, efficient thermal management, and infrared stealth simultaneously. In this study, a carbon aerogel, integrating electromagnetic attenuation and thermal management, is innovatively constructed using collagen fibers (CFs) extracted from leather waste with poly(vinyl alcohol) (PVA) via cyclic impregnation and high-temperature carbonization. This carbon aerogel is fabricated by hydrogen-bond-driven assembly of collagen fibers and polyvinyl alcohol, followed by high-temperature carbonization, and then loading of molybdenum disulfide-coated silver nanowires (AgNWs@MoS2) nanoparticles via cyclic impregnation. Notably, the CFs/AgNWs@MoS2 Carbon (CAMC) aerogel exhibits excellent electromagnetic interference shielding performance with an electromagnetic interference shielding effectiveness (EMI SE) of 72.1 dB and an electromagnetic reflectivity of approximately 0.27. It also demonstrates outstanding microwave absorption characteristics, including a minimum reflection loss (RLmin) of -48.77 dB at 12.16 GHz and an effective absorption bandwidth (EAB) of 4.01 GHz at a thickness of 2.8 mm. Additionally, the aerogel possesses superior heat retention and infrared stealth performance, maintaining a deep purple color close to the ambient background when exposed to 160 °C. It further exhibits efficient solar-to-thermal energy conversion and heat generation capability with a surface temperature reaching 79.1 °C under 250 mW/cm2 irradiation. Impressively, the CAMC carbon aerogel achieves near-ideal impedance matching with an impedance ratio (Z) of 1. This work not only solves the difficult problem of carbon aerogel's single property with poor protection performance but also achieves the sustainable recycling and utilization of leather waste, demonstrating profound application prospects in electromagnetic protection and thermal regulation.