Polycrystalline polyphase W–Co–Fe compound nanoparticles synergistic carbon hydrophobic heterostructure for microwave absorption

Carbon-based absorbing materials play an important role in civil and military fields. Based on the supramolecular self-assembly strategy of particle dispersion system, depending on the high negative charge of phosphotungstic acid, it is self-assembled with positively charged dopamine hydrochloride by electrostatic action. A controlled experimental system is designed to study the effects of pH values, carbonization temperature and composition ratio on the morphology and properties of supramolecular structures, and realize the controllable preparation of efficient carbon-based microwave absorbing materials. Due to the large number of elements in phosphotungstic acid and CoFe2O4, polycrystalline polyphase W–Co–Fe compound nanoparticles supported nitrogen and phosphorus co-doped carbon nanocomposites were obtained by carbonizing the self-assembled precursor. This is conducive to the formation of multiple heterogeneous interfaces, and the charge accumulates on the interface of multiphase materials, inducing space charge polarization. The introduction of Fe and Co magnetic metal elements can increase the magnetic loss and form a magnetic-dielectric-conductance multi-loss matching microwave absorbing material. Benefit from high impedance matching and attenuation characteristics, the hydrophobic sample S700-35 wt% displays ultra-broad effective absorption bandwidth (EAB) below −20 dB of up to 12.3 GHz (4.6–16.9 GHz) at the thickness range of 1–5 mm, which can cover the C-X-Ku band. The EAB values below −10 dB reach 8.64 GHz at 3.1 mm (S700-30 wt%), 7.04 GHz at 2.2 mm (S700-35 wt%), respectively. The maximum absorption values are −53.1 dB (S700-30 wt%) and −54.4 dB (S700-35 wt%), respectively. This work provides a new way to realize the functional assembly of carbon-based absorbing materials and the regulation of absorbing properties.