Electromagnetic shielding performance of SiC/graphitic carbon-SiCN porous ceramic nanocomposites derived from catalyst assisted single-source-precursors

In this work, SiC nanowires and graphitic carbon (GC) including 2D reduced graphene oxide and graphene-liked ribbons modified polymer derived SiCN (SiC/GC-SiCN) porous ceramic monoliths were prepared via catalyst assisted single-source-precursor derived ceramic route. The inclusion of absorbents (e.g. graphitic carbon and SiC nanowires) significantly improved the electrical conductivity of the materials from 1.77 × 10⁻⁸ S/cm (pristine SiCN) to 0.56 S/cm. In turn, the electromagnetic interference shielding effectiveness (EMI SE) of the ceramic increased significantly from 4.0 dB to 19.2 dB. At the highest absorbent content, the SiC/GC-SiCN ceramics exhibit a high absorption power of 0.3 nW and an SE of 48.5 dB at thickness of 2 mm, which means more than 99.998 % of the EM wave is blocked. This work finds new avenue for the design of advanced electromagnetic shielding materials possessing strong absorption capability.