Carbon foams with Fe-organic network-derived Fe3O4 for efficient electromagnetic shielding

Carbon-based functional materials have attracted extensive attention of the materials research community in recent years. They are expected to be used in flexible wearable devices due to their certain remarkable properties such as light-weight, ability to form thin films and excellent electromagnetic shielding performance. Herein, we report a novel CNTs/Fe3O4/Melamine-based carbon foam functional materials which can be utilized for efficient electromagnetic shielding. The synthesis of this material relies on the in-situ growth of the metal-organic skeleton on the carbon-based skeleton structure and the subsequent heat treatment process. This method is effective in in - situ doping of Fe3O4 nanoparticles on the carbon matrix. Electromagnetic shielding performance experiments demonstrate that the total shielding effectiveness (SET) of a functional material with the thickness of 3 mm is as high as 46.41 dB in the X-band. It is reflection-dominated accounting for as high as reflection coefficient of 0.67. In addition, this material also exhibits good compression cycle performance. Even after 50 compression cycles, its SET remains 33.80 dB. Compared to the Melamine-based carbon foam, the electromagnetic shielding perfor- mance of the functional material is significantly improved, which is effectuated mainly due to innovative structural design of the functional material. The high conductivity CNTs, magnetic Fe3O4 and porous carbon skeleton structure form the synergistic effect of dielectric and magnetic losses, which significantly improves the electromagnetic shielding performance of the functional material.