Effective electromagnetic wave absorber of BN nanoribbons bonded with rGO by confined strategy

Reasonable component and structure design for absorbers are of great significance for improving their electromagnetic (EM) absorbing performance. Aiming at the high-efficiency and light-weight EM wave absorbing materials, boron nitride nanoribbons covalent bonding with reduced graphene oxide (BN/rGO) with a unique stem-leaf structure were prepared by confined strategy of freeze-casting and heat treatment. The BN nanoribbons directly adjusted the dielectric constant of rGO, as well as avoided the stacking and agglomeration of rGO sheets, which was beneficial to improve the impedance matching and enhance the polarization loss. The BN/rGO exhibited outstanding EM wave absorbing properties. When the filling ratio was 5 wt%, the reflection loss (RL) of BN/rGO/paraffin was −44.7 dB located at 3.0 GHz, and the effective absorption bandwidth (EAB) was 5.52 GHz (92 % of the Ku-band) at 2.00 mm. Meanwhile, the EAB was 2.48 GHz at 4.00 mm in C-band (4–8 GHz), which had surpassed most of the reported nonmagnetic materials. This work provided an effected strategy for the martial with light weight and broadband EM wave absorbing performance.