Designing Carbon-Foam Composites via Molten-State Reduction for Multifunctional Electromagnetic Interference Shielding

Advanced electromagnetic interference (EMI) shielding materials are in great demand because of the severe electromagnetic population problem caused by the explosive growth of advanced electronics. Besides superior EMI shielding properties, the mechanical strength of the shielding materials is also critical for some specific application scenarios (e.g., shielding cases and shielding frames). Although most reported EMI shielding materials possess good shielding properties and lightweight characteristics, they usually exhibit a poor mechanical strength. Concurrently, multifunctionality is also essential for the application of the EMI shielding material. This study develops a molten-state-based in situ reduction strategy to fabricate an efficient EMI shielding composite, enabling the uniform dispersion of Co-nanoparticles on the carbon form matrix while featuring a high density of defects. This ensures the high mechanical strength of the composite due to the presence of a huge interface and significantly enhances the EMI shielding performance. The composite achieves an optimal shielding effectiveness of 32.6 dB and compressive strength of 38.31 MPa, respectively, improved by 65.4 and 123.4% compared to the pristine carbon foam. Simultaneously, the composite also exhibits desirable electrochemical and photothermal conversion properties. This research offers insights into the design of composites that excel in electromagnetic interference shielding, mechanical robustness, and multifunctionality.