Self-supporting Fe3C@C composites derived from MOF/chitosan films for electromagnetic interference shielding and Joule heating

Abstract

High-performance electromagnetic interference (EMI) shielding materials have emerged as a pivotal solution for mitigating the growing challenges of electromagnetic pollution. A straightforward approach was developed to prepare a series of self-supported Fe₃C nanoparticles on carbon sheets (Fe₃C@C) by regulating the Fe-MOF and chitosan (CS) composite film (Fe-MOF@CS), followed by carbonization treatment. Characterization results reveal that the Fe₃C nanoparticles anchored on carbon sheets generate abundant heterogeneous interfaces, creating a porous architecture with interconnected conductive networks. This unique microstructure significantly enhances the electrical conductivity while simultaneously boosting magnetic loss capabilities, leading to superior electromagnetic interference shielding performance. The optimized Fe₃C@C-0.6 composites demonstrated exceptional EMI shielding performance in the X-band, achieving an average shielding effectiveness of 67.5 dB at a minimal thickness of 0.7 mm corresponding to an attenuation of 99.99998% of incident electromagnetic waves. Notably, the Fe₃C@C-0.6 composites exhibit multifunctional characteristics including efficient Joule heating capability (the surface temperatures can reach up to 175.8 °C at 4 V) and excellent flame retardancy.