Hierarchical sponge-like Ag nanowire aerogel@metal-organic frameworks derived multifunctional phase-change thermal energy storage materials with superior photothermal conversion and microwave absorption

To address the low-temperature and electromagnetic pollution challenges for integrated electronics in extreme-cold radar stations, this study develops a multifunctional composite designed to synergistically integrate photothermal conversion, phase-change energy storage, and microwave absorption, enabling renewable solar energy use for adaptive thermal management and electromagnetic protection. The multifunctional material n-22/Ag@Fe-C@SiO 2 is fabricated by in-situ growing MIL-100(Fe) on a 3D silver nanowire aerogel, followed by carbonization, impregnation with n-docosane (n-22), and SiO₂ encapsulation. The AgNW framework provides a 3D conductive/thermal network, while the MOF-derived Fe-C modulates the dielectric constant. The Fe-C component enhances the specific surface area and enables precise modulation of the dielectric constant. The n-22/Ag@Fe-C@SiO 2 exhibited an energy storage density as high as 180.1 J/g. The synergistic effect among the localized surface plasmon resonance (LSPR) of silver, the conjugation effect of graphitic carbon, and the multistage reflection within the 1D@3D hierarchical sponge structure led to an outstanding photothermal conversion efficiency of 90.13%. The MOF-derived Fe-C on AgNWs synergistically enhances microwave absorption by boosting interface polarization and magnetic loss. The resulting n-22/Ag@Fe-C composite achieves an impressive minimum reflection loss of −57.87 dB and an effective absorption bandwidth of 5.28 GHz, demonstrating strong potential for integrated thermal management and electromagnetic protection.