Fabrication of novel silicon carbide-based nanomaterials with unique hydrophobicity and microwave absorption property

摘要

Novel SiC-based nanomaterials, namely the nitrogen and aluminum co-doped SiC@SiO(2)core-shell nanowires and nitrogen-doped SiO2/Al(2)O(3)nanoparticles, have been fabricated through a facile thermal treatment process based on the chemical vapor deposition and vapor-liquid reaction. These nanomaterials show remarkable hydrophobicity with a water contact angle (CA) over 140 degrees, which are aroused by the surface zigzag morphology of the nanostructures and the hydrocarbyl groups generated during the preparation process. Moreover the nanocomposites also exhibit relatively prominent microwave absorption (MA) properties in the frequency range of 2.0-18.0 GHz. The minimum reflection loss (RL) value as low as -23.68 dB can be observed at 14.16 GHz when the absorber thickness is 2.6 mm with a loading rate of 16.7 wt. And the nanocomposites-based absorbent can achieve an effective absorption bandwidth (RL < -10 dB) of 4.48 GHz with the absorbent thickness of 2.5 mm. This enhanced microwave attenuation performance can be attributed to multiple polarizations and perfect impedance matching conditions, as well as multiple internal reflections. These marvelous properties make these N and Al co-doped SiC@SiO(2)core-shell nanowires and N-doped SiO2/Al(2)O(3)nanoparticles display extensive application potential as MA materials in harsh environment.