Highly porous SiC derived from pine wood was successfully prepared, and the finely interconnected porous structure was well maintained even suffering from two-step high temperature reaction. Research shows that the unique porous structure and high density of stacking faults played a synergistic role in enhancing EM absorbing performance. It solves the problem of poor performance and instability of traditional electromagnetic wave absorbing materials at high temperature.and demonstrate that rationally design of biomass-derived SiC material is a promising way of developing high performance absorber.
The traditional electromagnetic (EM) absorbing materials suffers from the poor performance and instability at high temperature, greatly hindering their wide application. Herein, pine wood-derived SiC with porous structure and plentiful defect sites was synthesized by carbonization and subsequent chemical vapor infiltration process. The influence of drying pretreatment way (freeze drying vs thermostatic drying), carbonization temperature and Si powder/carbon ratio on structure and electromagnetic (EM) wave absorption performance were studied in detail. The optimized SiC with plentiful pore structure and numerous stacking faults showed superior EM wave absorption abilities with a minimum RL value of −42 dB and the effective bandwidth of 14.4 GHz (3.6–18 GHz). The synergistic effect between porous structure inherited from pine wood and stacking faults distinctly enhanced EM wave absorbing performance of SiC. This work demonstrate that rationally design of biomass-derived SiC material is a promising way of developing high performance absorber.Zum Volltext