Cost-effective carbonized waste corrugated boards with surface decorated by SiC@C nanofibers and nanospheres for electromagnetic interference shielding

Waste corrugated boards reformed by wood fiber are good precursor to be carbonized into multihole carbon materials for high-value utilization. Herein, waste corrugated board was recycled to fabricate functional carbon-silicon composite by the heat treatment under 1100 °C. The SiC nf and SiC nano-sphere were self-assembled during the carbothermal reduction to construct the nano-porous structure. The carbon coating on SiC can enhance the interfacial polarization effect. Owing to this gradient structure, the as-prepared carbon-silicon carbide composite exhibited a well electromagnetic interference shielding effectiveness (EMI SE) of ∼49.46 dB in the X-band. Moreover, its absolute EMI SE is observed to be ∼1561.51 dB∙cm 2 ∙g −1 , which reveals excellent EMI shielding performance combined with light weight. This good overall performance, along with environmentally friendly, ease of mass production, pave way for the large-scale practical applications in EMI shielding.