Electrospinning fabrication and ultra-wideband electromagnetic wave absorption properties of CeO2/N-doped carbon nanofibers

Abstract

The impedance mismatch of carbon materials is a key factor limiting their widespread use in electromagnetic (EM) wave absorption. In this work, the novel CeO2/nitrogen-doped carbon (CeO2/N-C) nanofiber was prepared to solve the problem by electrospinning and sintering. X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) analyses demonstrated CeO2 was successfully loaded onto the surface of partially graphitized carbon fibers. Different sintering temperatures change the graphitization degree of material, and the oxygen vacancy structure of CeO2 and defects from N doping optimize the impedance matching of the material. When the sintering temperature reaches 950 °C, CeO2/N-C fiber possesses the minimum reflection loss (RLmin) value of −42.59 dB at 2.5 mm with a filler loading of only 3 wt.% in polyvinylidene difluoride (PVDF). Meanwhile, the CeO2/N-C fiber achieves a surprising wideband (8.48 GHz) at a thickness of 2.5 mm, covering the whole Ku-band as well as 63% of the X-band at the sintering temperature of 650 °C. This work provides the research basis for widely commercial applications of carbon-based nanofiber absorbers.