Facile synthesis and microwave absorption performance of coated carbon nanotubes by porous Fe3O4 C nanorods

Composites consisting of porous Fe3O4 nanorods grown on carbon nanotubes coated with carbon film were obtained through a facile method. According to its relative permittivity and permeability, the microwave absorption abilities of such composites were examined. Impedance matching was optimized by carbon nanotubes addition to produce a strong absorption ability and corresponding effective frequency bandwidth. Porous Fe3O4 and amorphous carbon film provided greater polarization and dipole centers which improved microwave absorption abilities. The minimum reflection loss (R-L) of such composites reached - 37.50 dB at 2.0 mm thickness, while, a minimum R-L of - 35.70 dB and corresponding frequency bandwidth of 3.06 GHz was also obtained at 1.5 mm thickness. These results revealed that such composites presented superior absorption performance and could be very useful in the microwave absorption field.