Broadband and efficient microwave absorption of SiCnw@PDDA/MXene composites achieved by interfacial engineering and dielectric optimization

Abstract

Electromagnetic pollution poses an increasingly severe challenge, making the development of highly efficient and stable absorptive materials a current research priority. Silicon carbide (SiC) offers outstanding high-temperature resistance, tunable dielectric properties, and low density, while MXene demonstrates exceptional electromagnetic loss potential due to its high conductivity, unique layered structure, and abundant surface functional groups. Combining these two materials holds promise for further optimising absorptive performance through synergistic effects. This study employs electrostatic self-assembly to fabricate SiC/MXene composite absorbers, systematically investigating the regulation of electromagnetic parameters by MXene content and composite microstructure. Results indicate that the heterointerface formed between SiC and MXene induces a pronounced interfacial polarisation effect. MXene's high conductivity significantly enhances conductive loss, while SiC optimises impedance matching efficiency through dielectric regulation. At a mass ratio of SiCnw to MXene of 5 : 1 and a matched thickness of 2.316 mm, the composite material achieved a minimum reflection loss (RL_min) of -54.88 dB, with an effective absorption bandwidth (EAB, RL ≤ −10 dB) spanning 5.185 GHz. The enhanced microwave absorption is attributed to the synergistic optimization of conductive loss, dielectric loss, and heterogeneous interfacial polarization. This work provides an experimentally accessible strategy for designing lightweight and thermally stable SiCnw/MXene absorbers with broadband absorption characteristics.