Abstract: As electromagnetic (EM) pollution intensifies, EM protection materials have garnered significant attention. However, the development of lightweight and efficient EM protection materials still faces numerous challenges. In this work, a bilayered metal-organic framework (MOF), specifically zeolitic imidazolate framework-8@zeolitic imidazolate framework-67 (ZIF-8@ZIF-67), is initially prepared. Subsequently, through a combination of electrospinning and high-temperature carbonization processes, a heterodimensional structure featuring carbon-based dodecahedrons tandemly arranged on carbon nanofibers was obtained. The carbonization at various temperatures modulated the nanofibers' conductive network and graphitization of dodecahedrons, thereby regulating the dielectric response, which is crucial for tuning the EM properties of the material. Furthermore, dielectric-magnetic synergy also plays a certain role in optimizing microwave absorption performance. The Co-CHD@CNF800 with 60 wt% loading content demonstrates a minimum reflection loss (RL) of -53.6 dB at 1.83 mm, while 40 wt% loading content exhibits a maximum effective absorption bandwidth (EAB) of 6 GHz at 2.67 mm. Additionally, Co-CHD@CNF1000 with 80 wt% exhibits remarkable electromagnetic interference (EMI) shielding performance. Importantly, an EM energy conversion device has been constructed that can effectively recover and utilize harmful EM energy. This research presents an innovative approach to the development of lightweight and efficient EM protection materials and devices.

Key words: Metal-organic framework, Carbon hollow dodecahedron, Carbon nanofiber, Microwave absorption, Electromagnetic interference shielding