Electromagnetic Interference Shielding by Reduced Graphene Oxide Foils

The pursuit of materials to avoid problems associated with electromagnetic pollution has become a relevant research topic. Here, we report the exceptional electromagnetic interference (EMI) shielding performance of freestanding reduced graphene oxide (rGO) foil produced by thermal reduction of graphene oxide (GO). The rGO foil with a thickness of 93.1 ± 12.4 μm reaches an efficient EMI shielding effectiveness (SE) value of 61.6 dB at 12.4 GHz. The excellent performance of the rGO foil is attributed to the thermal reduction of the GO foil, which restores the electrically conductive network, resulting in the electrical conductivity of 1.17 × 104 S m–1. To obtain a more complete profile of the EMI shielding performance of the rGO foil, measurements are performed in G- and C-bands, thus becoming the first study on the EMI shielding performance of an rGO film on a broad frequency range beyond the so-called X-band. The material sustains an EMI shielding efficiency higher than 99.999% over the frequency bands investigated, greatly desired in a wide range of commercial applications in this field.