In situ synthesis of CoFe2O4 nanocrystals decorated in mesoporous carbon nanofibers with enhanced electromagnetic performance

CoFe2O4 nanocrystals decorated in mesoporous carbon nanofibers (CoFe2O4/C NFs) are prepared by electrospinning and subsequent calcination. The CoFe2O4/C NFs exhibit optimal electromagnetic waves absorption performance. The minimum reflection loss (RL) of CoFe2O4/C NFs reaches -14.0 dB at a frequency of 9.0 GHz and a thickness of 3.5 mm with low doping mass of 20 wt%. In addition, the maximum effective absorption bandwidth range (RL <= -10 dB) is 3.6 GHz with a thickness of 2.5 mm. The interfacial polarization effect of the material itself and the synergistic effect between the binary components are promoted by combining one dimensional (1D) carbon nanofibers with magnetic CoFe2O4 spinel nanocrystals. Therefore, this strategy can achieve good impedance matching and effectively improve the absorbing properties of our materials. This work shows that enriching the diversity of material loss mechanisms, constructing hierarchical nanostructures of fibers, the simple and mature preparation methods can make CoFe2O4/C NFs composites a potentially new-type of microwave absorbing material which can be easily put into production. (C) 2020 Elsevier B.V. All rights reserved.