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

作　　者：Yunlong Lian Binhua Han Dawei Liu Yahui Wang Honghong Zhao Ping Xu Xijiang Han Yunchen Du 

机构地区：[1]MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage,School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin 150001,People’s Republic of China

出　　处：《Nano-Micro Letters》2020年第11期141-153,共13页纳微快报（英文版）

基　　金：supported by National Natural Science Foundation of China(21676065 and 21776053)。

摘　　要：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 in carbon nanosheets,the relative complex permittivity and dielectric loss ability are constantly enhanced through conductive loss and polarization relaxation.The different dielectric properties endow 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.

关 键 词：Solvent-free synthesis Tungsten carbide/carbon composite Ultrafine nanoparticle Microwave absorption Dielectric loss 

分 类 号：TB383.1[一般工业技术—材料科学与工程]