Hollow N doped carbon/SiCN hierarchical structures for thermostable electromagnetic absorptions

Electromagnetic absorption materials present widespread application prospects. The thermal oxidative aging issues for electromagnetic absorption materials have received little attention. In this paper, N-doped carbon tubes, and the SiCN ceramics are combined to realize thermostable electromagnetic absorptions. The hierarchical structures show significantly enhanced broadband electromagnetic absorption with an optimal RL of -53.61 dB at 14 GHz under a thickness of 2 mm. The effective electromagnetic absorption bandwidth reaches 5.53 GHz, and the coverage range is 11.88–17.41 GHz. More importantly, after 1 h calcination at 300 °C, the optimum RL of NCT/SiCN-1 h is still -45.67 dB under the thickness of 2.5 mm. The effective electromagnetic absorption bandwidth increases to 5.95 GHz, and the coverage range is 10.69–16.64 GHz. Our work proves the possibility for improving the thermostable electromagnetic absorptions of carbon materials, and provides referencing ways for the design of thermostable electromagnetic absorption materials.