Preparation and microwave absorption properties of carbon nanotubes/iron oxide/polypyrrole/carbon composites

•Carbon-coated Fe3O4 modified carbon nanotube/polypyrrole composites were prepared.•The weight percentage of the Fe3O4 nanoparticles was only 8.8 %.•The nanocomposites exhibit excellent microwave absorption properties.•The maximum reflection loss is -53.07 dB at 13.92 GHz with a thickness of 2.2 mm. Carbon nanotubes/iron oxide/polypyrrole/carbon composites were prepared by in situ polymerization. The weight percentage of the iron oxide nanoparticles was only 8.8 %. The microwave absorption performance of the carbon nanotubes/iron oxide/polypyrrole/carbon composites was researched and the corresponding filler loading of paraffin in the tested samples was 80 wt%. The reflection loss appeared at 13.92 GHz, which was -53.07 dB, the corresponding effective absorption bandwidth was 6.4 GHz, and the matching thickness was 2.2 mm. The synthetic composite materials have both magnetic loss and dielectric loss. The combination between different materials and the improved impedance matching can enhance the electromagnetic wave performance. At the same time, the composite materials have multiple interface and multilayer core-shell structure, which was beneficial to absorbing electromagnetic waves.