15August2020

Nano-Micro Letters

Solvent-Free Synthesis of Ultrafine Tungsten Carbide Nanoparticles-Decorated Carbon Nanosheets for Microwave Absorption

Yunlong Lian1, Binhua Han1, Dawei Liu1, Yahui Wang1, Honghong Zhao1, Ping Xu1, Xijiang Han1, *, Yunchen Du1, *

Abstract | Support Info
icon-htmlFull Text Html
icon-pdf-smPDF w/ Links
icon-citExport Citation
Figures
+Show more

Nano-Micro Lett. (2020) 12: 153

First Online: 18 July 2020 (Article)

DOI:10.1007/s40820-020-00491-5

*Corresponding author. E-mail: yunchendu@hit.edu.cn (Yunchen Du); hanxijiang@hit.edu.cn (Xijiang Han)

 

Abstract

 


Toc

Carbides/carbon composites are emerging as a new kind of binary dielectric systems with good microwave absorption performance. Herein, we obtain a series of tungsten carbide/carbon composites through a simple solvent-free strategy, where the solid mixture of dicyandiamide (DCA) and ammonium metatungstate (AM) is employed as the precursor. Ultrafine cubic WC1-x nanoparticles (3~4 nm) are in situ generated and uniformly dispersed on carbon nanosheets. This configuration overcomes some disadvantages of conventional carbides/carbon composites and is greatly helpful for electromagnetic dissipation. It is found that the weight ratio of DCA to AM can regulate chemical composition of these composites, while less impact on the average size of WC1-x nanoparticles. With the increase of carbon nanosheets, the relative complex permittivity and dielectric loss ability are constantly enhanced through conductive loss and polarization relaxation. The different dielectric property endows these composites with distinguishable attenuation ability and impedance matching. When DCA/AM weight ratio is 6.0, the optimized composite can produce good microwave absorption performance, whose strongest reflection loss intensity reaches up to -55.6 dB at 17.5 GHz and qualified absorption bandwidth covers 3.6-18.0 GHz by manipulating the thickness from 1.0 to 5.0 mm. Such a performance is superior to many conventional carbides/carbon composites.


 

Keywords

Solvent-free synthesis, Tungsten carbide/carbon composite, Ultrafine nanoparticle, Microwave absorption, Dielectric loss

 View: Full Text HTML | PDF w/ Links