Flexible Mo₂C‐Modified SiC/C Nanofibers for BroadBand Electromagnetic Wave Absorption

Abstract

Materials with 1D structure exhibit a remarkable advantage for losing electromagnetic (EM) wave energy. Herein, flexible Mo2C‐modified SiC/C nanofibers (Mo‐SiC/C NFs) are synthesized for the first time by co‐electrospinning and subsequent high‐temperature pyrolysis, using polycarbosilane (PCS) and molybdenum acetyl acetone (MoO2(acac)2) as precursors. It is found that the polymer derived temperature of PCS is significantly decreased by introducing MoO2(acac)2, as well as endowing the SiC/C NFs with good flexibility, high crystallinity, and remarkable microwave absorption performance. The as‐prepared fibers dispersed in paraffin with a low filler loading (15 wt%) exhibit a minimum reflection loss (RL, dB) of ‐62.5 dB, and a wide effective absorption bandwidth (EAB, RL<‐10 dB) of 6.8 GHz at 2.75 mm. Meanwhile, the EAB of the hybrid can cover the whole X‐band and most of the C‐band by modulating its thickness. These high‐efficient performances mainly originate from the specific 1D microstructure, abundant interfaces and defects, and synergistic effect among SiC, Mo2C, and C matrix. Thus, this work offers a way to explore flexible SiC/C NFs as a promising candidate with lightweight and wide EAB for EM wave absorption.

Polymer‐Derived High‐Temperature Nonoxide Materials: A Review

“…[166] Mo 2 C-modified SiC/C nanofibers were also similarly made for electromagnetic absorption and demonstrated outstanding performance. [167] As shown in Figure 21, the electromagnetic wave absorption for the Fe-SiC fibers comes from crystalline SiC, turbostratic C, and C-coated Fe x Si y . The extended interfaces for the nanoscale phases and the defective interface structures help to reflect and scatter the electromagnetic waves.…”

State-of-the-art in carbides/carbon composites for electromagnetic wave absorption

“…As for multicomponent composites with two different carbides, one of them usually refers to those candidates that have very small particle size and are easily available under mild conditions, e.g., Mo 2 C and ZrC. 251 , 350 , 354 , 355 For example, Yuan et al. obtained 1D Mo 2 C/SiC/C fibers by the pyrolysis of PCS/MoO 2 (acac) 2 /PVP co-electrospinning fibers, and the uniform dispersion of Mo 2 C and SiC nanoparticles could generate abundant interfaces, defects, and synergistic effect, thus resulting in broad EM response with EAB of 6.87 GHz.…”

“…obtained 1D Mo 2 C/SiC/C fibers by the pyrolysis of PCS/MoO 2 (acac) 2 /PVP co-electrospinning fibers, and the uniform dispersion of Mo 2 C and SiC nanoparticles could generate abundant interfaces, defects, and synergistic effect, thus resulting in broad EM response with EAB of 6.87 GHz. 354 Yang et al. coated MoO 3 /PDA microspheres with MXene nanosheets, and converted the intermediate composite into ternary Mo 2 C/C/MXene composite, which also displayed strong RL intensity over −60 dB and moderate EAB.…”

In situ construction of ZIF-67 derived Mo2C@cobalt/carbon composites toward excellent electromagnetic wave absorption properties

“…Molybdenum carbide (Mo 2 C) has been recently emerging as a promising EM wave absorbent because of its excellent dielectric properties, chemical stability, and tunable structure [8]. Especially, when combined with carbon materials, the synergistic effect renders Mo 2 C-based composites with brilliant EM wave absorption performance due to polarization loss and conductive loss [9].…”