Vanadium nitride@carbon nanowires with inner porous structure for high-efficient microwave absorption

Highlights: • VN@N-doped carbon NWs with inner porous structure was successfully prepared. • The min RL of the hybrid with 20 wt% is −60.2 dB and max EAB of 5.8 GHz. • Enhance property is due to the 1D porous structure, N-doped C shell and VN grains. Herein, N-doped carbon coated vanadium nitride nanowires (VN@NC NWs) with inner porous structure were synthesized by coating a thin layer of a carbon precursor of polydopamine (PDA) on ultralong V₂O₅ NWs followed by nitridation. The amorphous carbon coating could ensure the one-dimensional (1D) structure, as well as produce the inner pores during nitriding progress. The formational 1D porous architecture, high-crystallized VN nanoparticles and homogeneous N-doped carbon coating synergistically improved the materials' impedance match and thus enhanced their microwave absorption performances. The minimum reflection loss (RL_min) of the optimal samples/paraffin hybrid with 20 wt% was −60.2 dB with an effective absorption bandwidth (EAB, RL < −10 dB) of 3.8 GHz at a thickness of 2.75 mm, and its maximal EAB of 5.8 GHz with a RL_min of −49.8 dB at a thickness of 2.25 mm. Hence, the inner porous VN@NC NWs in this case would be as a high-efficient microwave absorber.