Heterogeneous Interface Engineering Enabled ZnO/C Hybrid Aerogels for High-Performance Radar-Infrared Compatible Stealth

Pure carbon aerogels are constrained by insufficient electromagnetic loss mechanisms and poor compatibility between radar wave absorption and infrared stealth. Here, a heterogeneous interface engineering strategy is developed to construct ZnO/C hybrid aerogels derived from ZIF-8 and chitosan, featuring ZnO/C interfacial structures and hierarchical meso/macroporous structures. The hybrid aerogel sample, carbonized at 800 °C (CA-Z-800), achieves optimal microwave absorption performance with a minimum reflection loss (RLmin) of -35.74 dB and an effective absorption bandwidth (EAB) of 4.55 GHz at a matching thickness of only 1.5 mm. Simultaneously, it maintains effective infrared stealth performance with a low thermal conductivity of 0.151 W/(m·K), a surface temperature rise of only ∼4 °C, and infrared emissivity of 0.654 (3-5 μm) and 0.638 (8-14 μm). Notably, although increasing carbonization temperature to 900 °C further reduces emissivity to 0.601 and 0.595, it severely degrades impedance matching, leading to a much weaker reflection loss (-13.53 dB) and a narrower effective bandwidth (2.85 GHz). This trade-off reveals that CA-Z-800 represents the optimal balance for radar-infrared compatible stealth. Density functional theory (DFT) calculations elucidate charge redistribution and enhanced interfacial polarization at the ZnO/C interfacial structures, while computer simulation technology (CST) simulations confirm strong microwave attenuation. Systematic control of pyrolysis temperature and ZnO microstructure enables tuning of dielectric properties and thermal insulation. These findings demonstrate a correlation between radar absorption and infrared suppression, with CA-Z-800 achieving the optimal balance among the samples tested.