Radar-stealth and thermal-insulating MOF-derived cellulose-carbon aerogels for broadband electromagnetic wave absorption

Abstract

Considering the challenges posed by severe electromagnetic wave pollution and escalating international tensions, there is a critical need to develop advanced electromagnetic wave absorbing (EMWA) materials that integrate radar stealth and thermal insulation capabilities. In this study, we have synthesized three-dimensional (3D) porous composites comprising V₂O₃ nanoparticles embedded in Juncus effusus cellulose-derived carbon aerogels (VCA) using a self-templating method followed by high-temperature pyrolysis. The V₂O₃ nanoparticles possess a 3D V-V framework and a relatively narrow bandgap, facilitating the Mott transition for enhanced conductivity. Furthermore, their uniform dispersion on hollow carbon tubes of Juncus effusus promotes efficient electron transfer and creates numerous heterogeneous interfaces. Consequently, VCA-2 demonstrates outstanding EMWA performance, achieving a minimum reflection loss of −63.92 dB at a matching thickness of 2.0 mm and a maximum effective absorption bandwidth of 8.24 GHz at a thickness of 2.44 mm, covering nearly half of the tested frequency range. Additionally, the radar cross-section reduction reaches a peak value of 29.40 dB m², underscoring the excellent radar stealth capabilities of the material. In summary, VCA exhibits exceptional EMWA, radar stealth, and thermal insulation properties, highlighting its potential for multifunctional applications in EMWA material development.