Wood-Derived 3D Conductive Cellular Bio-C@YB2C2 Ceramics for Efficient Electromagnetic Shielding and Joule Heating

The electromagnetic interference shielding effectiveness (EMI SE) of materials is highly related to their microstructures. Mimicking nature is an effective and useful strategy for designing high performance materials, even though it remains a great challenge. Herein, a biomimetic, anisotropic, robust wood-derived 3D conductive Bio-C@YB 2 C 2 framework was synthesized by in situ boron/carbon thermal reduction reaction on the carbonized wood template. The as-obtained Bio-C@YB 2 C 2 composites accurately inherit the specific microstructure of natural wood, providing pathways for terahertz wave dissipation. The thermal and electrical conductivity of composites increased with the content of layered superconductor YB 2 C 2 coated on the surface of Bio-C. The resulting Bio-C@30YB 2 C 2 ceramic exhibits exceptional performance, including a high thermal conductivity of 12.36 W·m −1 ·K −1 , an outstanding electrical conductivity of 204.13 S·cm −1 , and an efficient Joule heating performance, reaching 173.3°C at an applied voltage of 1.5 V. Meanwhile, it demonstrated a remarkable EMI SE (55.5 dB) in the X-band (8.2–12.4 GHz) for the sample with 1.5 mm thickness and normalized EMI SE/ t value as high as 37.0 dB·mm −1 , surpassing numerous other EMI shielding materials and their composites at equivalent thicknesses. It was due to the multiple reflections in the vertically aligned and densely interconnected microchannels, conduction loss and interfacial polarization at the interface of Bio-C@30YB 2 C 2 , and the superconductivity of YB 2 C 2 . This approach is anticipated to provide novel insights for designing ultra-high temperature electromagnetic shielding and electric heating materials.