Multifunctional Cellulose/rGO/Fe3O4 Composite Aerogels for Electromagnetic Interference Shielding

Cellulose/reduced graphene oxide (rGO)/Fe3O4 aerogels exhibiting strong electromagnetic wave absorption were prepared by a green, simple, and scalable coprecipitation process. With rGO loading of 8 wt % and Fe3O4 content of approx. 15 wt %, the electromagnetic interference shielding effectiveness (EMI SE) of the cellulose/rGO/Fe3O4 aerogel with 0.5 mm thickness reached 32.4-40.1 dB at 8.2-12.4 GHz. The EMI shielding performance of cellulose/rGO/Fe3O4 aerogels was higher for larger rGO loading (varied between 3 and 8 wt %) and greatly improved on increasing the sample thickness (varied between 0.5 and 2 mm). At 2.0 mm thickness, SE values of 49.4-52.4 dB were reached. Absorption plays a major role in the EMI shielding mechanism of cellulose/rGO/Fe3O4 aerogels. The multireflection of microwaves and impedance matching provides the highly efficient EMI shielding caused by the combined effects of the porous structure, rGO sheets, and Fe3O4 nanoparticles. The results demonstrate that these lightweight aerogels are suitable for EMI shielding.