Design of porous SiC/MnO2 bulk composite with improved absorption of low-frequency electromagnetic waves

Silicon carbide (SiC) is expected to be the new-generation electromagnetic wave (EMW) absorber. In this context, the SiC/C composites were first prepared through a hydrothermal method using glucose as the carbon source. Then SiC/MnO 2 composites were fabricated by a second hydrothermal reaction using potassium permanganate (KMnO 4 ) as raw material. With glucose content increased to 10 wt%, the composition exhibited outstanding EMW absorption performance with the minimum reflection loss value of − 55.7 dB at the frequency of 2.1 GHz, and effective absorption bandwidth can cover the entire S-band by adjusting sample thickness. Therefore, the SiC/MnO 2 composites present a promising EMW-absorbing material for low-frequency applications.