CNT coatings grown on the outer and inner surfaces of magnetic hollow carbon fibers with enhanced electromagnetic interference shielding performance†
High-performance electromagnetic interference (EMI) shielding materials have attracted more and more attention to address the increasingly serious problem of radiation pollution. The preparation of lightweight carbon fiber-based multiple-system materials with excellent EMI shielding performance has so far proven to be elusive. Herein, hollow polyacrylonitrile (PAN)–Fe3O4 fibers are employed to fabricate magnetic hollow carbon fibers with carbon nanotube (CNT) coatings grown on the outer and inner surfaces via a chemical vapor deposition (CVD) process. We have achieved the fabrication of a lightweight material with excellent EMI shielding performance, which can be attributed to the synergistic effect of the CNT coating, Fe3C (Fe3O4 converts to Fe3C after the CVD process) and the one-dimensional (1D) hollow structure. The EMI shielding performance is up to 80 dB and the density of the material is only ∼1.0 g cm−3. This material could be widely applied in wearable electronics, robot joints, precision instrument protection, and so on.