Enhancing the middle frequency X-band electromagnetic wave absorbing through porous defect engineering on MoC x carbon hybrids and heat-insulating aerogel

Abstract

AbstractControlling the porous defects in MoCx-carbon hybrids has been presented as an effective strategy for enhancing electromagnetic wave (EW) absorbing ability. To homogeneously distribute MoCxhetero-units into carbon matrix with high porosity and defect is of significance but hard to achieve. Herein, an excellent temperature-induced porous defect has been successfully constructed in the metallic Co-doped MoCxcarbon composite. The proper calcination temperature on the “Host-Guest” structural CoMo-based crystalline precursor has derived the homogeneously distributed metallic Co and MoCxparticles with the high number of mesoporous of ~ 20 nm and interfacial defects. Owing to the brilliant synergistic effect of polarization, magnetic loss and impedance matching, the superiorRLminof -47.72 dB at 11.76 GHz at the thickness of 2.0 mm and a wide effective absorption bandwidth (EAB) of 4.58 GHz (7.44 ~ 12.02 GHz) covered the whole X-band at the thickness of 2.5 mm forη-MoC/Co@NC-800 were observed. More importantly, the excellent heat-insulating performance of theη-MoC/Co@NC-800 derived ultralight aerogel composite has been developed, which is better than commercial materials. This work provides a valuable insight to facile constructing porous defects in EW absorbing materials and heat-insulating composite materials.