Vapor diffusion synthesis of rugby-shaped CoFe2O4/graphene composites as absorbing materials

•CoFe2O4 rugbies/graphene hybrids were synthesized using a vapor diffusion method.•PVP played a key role for the formation of CoFe2O4 rugbies.•CoFe2O4 rugbies/graphene composites showed excellent microwave absorbing property.

Rugby-shaped CoFe2O4/graphene composites were synthesized using a vapor diffusion method in combination with calcination. The morphologies and structures of the products were characterized by field emission scanning electron microscopy, X-ray diffractometer, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The magnetic and electromagnetic parameters were measured using a vibrating sample magnetometer and a vector network analyzer, respectively. Results show that rugby-shaped CoFe2O4 particles are distributed on graphene sheets. A minimum reflection loss (RL) of −39.0 dB is observed at 10.9 GHz for the sample with a thickness of 2.0 mm, and the effective absorption frequency (RL < −10 dB) ranges from 9.6 to 14.3 GHz, indicating the excellent microwave absorption performance of the products. The absorbing performance of the CoFe2O4 rugbies/graphene composites is better than that of the CoFe2O4 nanoparticles/graphene composites.

Graphical abstractCoFe2O4 rugbies/graphene composites were prepared using a vapor diffusion method followed by calcination. As-synthesized rugby-like CoFe2O4 particles were distributed on the graphene sheet. PVP played a key role for the formation of rugby-shaped morphology of CoFe2O4 particles. A minimum reflection loss of −39.0 dB was observed at 10.9 GHz for the CoFe2O4 rugbies/graphene composites with a thickness of 2 mm, and the effective absorption bandwidth was 4.7 GHz. The CoFe2O4 rugbies/graphene composites exhibited better microwave absorbing performance than that of the CoFe2O4 nanoparticles/graphene composites prepared without PVP.Figure optionsDownload full-size imageDownload as PowerPoint slide