Lamellar vanadium nitride nanowires encapsulated in graphene for electromagnetic wave absorption

Combination of three-dimensional (3D) nanoarchitectures and good electrical conductive performance is charming for the application of graphene-based composite. Herein, 3D lamellar composite of vanadium nitride nanowires encapsulated in reduced graphene oxide (VN NWs-rGO), in which interconnected VN NWs as skeletons with a porous structure were encapsulated in N-doped rGO nanosheets to form the lamellar structure, was synthesized by combination of freeze-casting and nitridation techniques. The as-prepared lamellar composite exhibited excellent EM wave absorbing properties: the min reflection loss (RL) value of the VN NWs-rGO/paraffin hybrid with a filler loading of 15 wt% was −41.5 dB at a thickness of 1.5 mm, with an effective absorption bandwidth (EAB, RL < −10 dB) reaching 3.9 GHz. The EM wave loss mechanism was in-depth explored in view of the complex 3D layered morphology, connected conductive network and multiple polarization relaxation of the developed material.