Structure optimization of vanadium nitride/carbon fibers with high stability for microwave absorption

As an efficient microwave absorber, vanadium nitride/carbon fibers (VN/C NFs) with high structure stability are fabricated by pyrolysis of electrospun precursor fibers containing zinc acetate (ZnAc) and vanadyl acetylacetonate (VO(acac)2). The one-dimenstional (1D) structure of VN/C NFs can be kept up 900 degrees C by introducing ZnAc in precursor fibers. And VN/C fibers are polycrystalline with diameters of 400-500 nm and lengths up to several millimeters, in which VN nanocrystals are uniformly dispersed in the carbon matrix. 15 wt% VN/C NFs dispersed in paraffin exhibited good microwave absorption performance. The minimum reflection loss (RL, dB) value is -56 dB at 4.0 mm, as well as the effective absorption bandwidth (EAB, RL < -10 dB) is 5.68 GHz at 2.2 mm. The strategy in this case can be adopted for preparing other transition metal nitrides with one-dimenstional structure.