Porous nitrogen-doped reduced graphene oxide composite films for efficient electromagnetic shielding

Graphene films are regarded as the next-generation electromagnetic interference (EMI) shielding material. However, the limited internal loss mechanisms in graphene films constrain their EMI shielding performance. In this work, porous nitrogen-doped reduced graphene oxide (porous N-rGO) composite films are prepared by vacuum filtration and a high-temperature annealing process using GO and micron-sized ZIF-8 particles as N source and template. After annealing, micron-sized ZIF-8 simultaneously introduces N heteroatoms into the efficient conductive network of rGO and creates a multi-level pore structure, which synergistically improves the shielding performance of composite films. The EMI shielding effectiveness of porous N-rGO composite film reaches 45.6 dB (48 μm) in the X-band, with an absolute shielding effectiveness of 35500.7 dB/cm²·g. Additionally, the porous N-rGO composite film with PDMS coating exhibits excellent flexibility and long-term durability. This flexible, high-performance EMI shielding composite film demonstrates great application potential in wearable electronic devices and aerospace fields.