Pressure-triggered dynamically tunable TiO2/CNFs@Co/C aerogel derived from MXene/PAN@ZIF-67 for broadband microwave absorption

Abstract

In increasingly complex electromagnetic environments, developing high-performance and dynamically tunable electromagnetic wave (EMW) absorption materials is essential. This study designed a pressure-responsive TiO₂/CNFs@Co/C elastic aerogel for efficient EMW absorption. A 3D interpenetrating structure consisting of Ti₃C₂T_x MXene-derived TiO₂ nanosheets, magnetic Co/C frameworks, and carbon nanofibers was constructed via electrospinning combined with in situ synthesis. This 3D interpenetrating structure constructs abundant heterogeneous interfaces, thereby enhancing interfacial polarization. The results demonstrate that the composite achieves an exceptionally broad effective absorption bandwidth (EAB) of 8.17 GHz at a thickness of 2.7 mm, with only 10 wt% filler loading. Additionally, the composite exhibits strong environmental tolerance, including hydrophobicity, stretchability, and thermal insulation. Notably, the alginate-induced elastic aerogels enable dynamic tuning from 6.4 to 18 GHz under compressive strains of 0% to 66%. This work designs dynamically tunable, high-performance EMW absorbers through component optimization and interface engineering, providing a promising strategy for the preparation of next-generation multifunctional intelligent EMW absorbers.