Preparation of Co doped carbon nanofibers composites synthesized by electrospinning and its microwave absorption properties

Carbon nanofibers with various contents of Co nanoparticle were synthesized by a two step process of electrospinning and subsequent heat treatment. The thermal stability,phase composition,microstructure and electromagnetic characteristics of the carbon nanofibers were characterized by differential scanning calorimetry-thermogravimmetric analysis (DSC-TGA),X-ray diffraction(XRD),scanning electron microscope(SEM) and vector network analyzer(VNA),and the microwave absorption performance was studied.The results indicate that the crystallinity of composite nanofibers is moderate when the carbonization temperature is 800℃.The amorphous carbon is partially converted into graphite and CoAc2 completely reduces to face-centered cubic structured Co nanoparticle. The fiber is intact and beads-on-string structure exists in the fiber networks. The electromagnetic characteristics of the carbon nanofibers significantly improve by the doping of Co. The Carbon nanofibers containing 7%(mass fraction) as fillers with thickness of 1.5mm exhibit maximum effective absorption bandwidth of 4.5GHz, and it is obviously improved compared to pure carbon nanofibers.