Facile Synthesis of Highly Defected Silicon Carbide Sheets for Efficient Absorption of Electromagnetic Waves

Stacking faults (SFs) within silicon carbide (SiC) are desired because these faults can enhance the electromagnetic (EM) absorption properties of the material. However, most reported SiC materials are prepared using expensive precursors possessing limited SFs. Herein, we report a facile and economical method to fabricate SiC sheets with a record-high SF density of over fourfold enhancement compared with previously reported SiC materials. The use of paper as a carbon source resulted in a 19-fold decrease in fabrication cost. The microstructure, defect structure, and EM wave absorption performance of the synthesized SiC sheets were investigated in detail. Enhancement of the SF content of the SiC sheets enabled significant interfacial dipole polarization, thereby imparting the sheets with superior EM wave absorption. SiC sheets with the maximum SF content obtained in this work revealed a minimum reflection loss of -22 dB and an effective EM wave absorption band (R_L < -10 dB) covering the frequency range of 12.8-18 GHz at a thickness of only 2.2 mm. Our research shows that paper-derived SiC can be used as an efficient EM wave absorption material and provides guidelines for synthesizing highly defected SiC sheets.