Facile preparation and extraordinary microwave absorption properties of carbon fibers coated with nanostructured crystalline SnO2

Tin dioxide (SnO2) nanocrystals were deposited on carbon fibers (CFs) by facile electrodeposition followed by annealing. The morphology and structure of the SnO2-coated CFs (SCCFs) were investigated by SEM, XRD, and TEM. Furthermore, the complex permittivity and permeability of SCCF/paraffin composites were measured, and the microwave absorption properties were simulated. SEM images reveal that SnO2 nanoparticles are uniformly coated on CFs. XRD and TEM studies show that the products consist of crystallized tetragonal rutile SnO2. The SCCF/paraffin composites exhibit excellent microwave absorption properties with the strongest reflection loss (RL) of −44.9 dB at 15.8 GHz, a matching thickness of 1.32 mm, and a bandwidth (RL < −20 dB) of 14.5 GHz. Relevant mechanism was proposed to elucidate the extraordinary microwave absorption properties of the SCCFs. It is believed that the SCCFs with crystalline SnO2 nanoparticles can become an ideal high-performance and light-weight microwave absorbing material.