Fabrication of 3D micro-flower structured BiFeO3 growing on rGO nanosheets for enhanced electromagnetic wave absorption

Abstract

Because of the distinctive structure and superior properties of graphene and its derivatives, which have been widely studied in the field of electromagnetic wave (EMW) absorption. However, the impedance mismatch caused by excessive conductivity of graphene and the single loss mechanism greatly limit its application. Herein, we prepare 3D micro-flower structured BiFeO3 grown on graphene oxide nanosheets (BiFeO3-rGO) to both improve the impedance matching and introduce abundant interfacial polarization loss. Moreover, the electromagnetic parameters of the materials are adjusted by changing the ratio of BiFeO3 and rGO to obtain prominent EMW absorption and satisfactory impedance matching performances. More importantly, the conductive loss and polarization loss of the materials are quantitatively analyzed to further explore the loss mechanism of EMW. As a result, the fabricated BiFeO3-rGO 1:1 and BiFeO3-rGO 2:1 both achieve remarkable EMW absorption performances with strong reflection loss (RL) of −49.5 and −45.3 dB and broad effective absorption bandwidth (EAB) of 8.12 and 8.08 GHz with a low filling contents of 5 %. This work demonstrates that polarization loss is as important as conduction loss and the key point to further improve the EMW absorption performance is to crack the code of polarization loss.