▎ 摘 要
In recent years, porous or layered magnetic materials have received increasing attention due to their low density and lightweight. In this work, porous BiFeO3 microspheres and three-dimensional porous BiFeO3 microsphere-reduced graphene oxide (RGO) composite (3D porous BiFeO3/RGO) were prepared by one-step etching processing using pure BiFeO3 particles as precursors. The precursor undergoes dissolution-recrystallization/reduction process, resulting in large amount of BiFeO3 fragments and graphene hybrid product, which forms 3D porous BiFeO3/RGO composite. Electromagnetic (EM) absorption performance measurements exhibit that at low thickness of 1.8 mm, porous BiFeO3/RGO composite can achieve reflection loss (R-L) value up to -46.7 dB and absorption bandwidth (defined by R-L < -10 dB) exceeding 4.7 GHz (from 12.0 to 16.7 GHz), testifying outstanding microwave absorbing performance. Compared with pure porous BiFeO3, improved EM wave absorption ability of as-prepared porous BiFeO3/RGO composite is attributed to interfacial polarization, multiple reflections, scattering, and appropriate impedance matching.