Excellent Microwave Absorption Performance in Porous Co/C Nanocomposites by Biomass Conversion

Yuqing Huang1,#

Ge Liu1,#

Dechun Liu2,Email

Meng Hao2,Email

Peitao Xie1

Zhicheng Shi3

Guohong Lin1,Email

1College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.
2Qingdao Municipal Hospital, Qingdao 266000, China.
3School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China.

#These authors contributed equally to this work.

Abstract

Carbon-based composites have been considered as the most popular lightweight microwave absorption materials and become a hot research topic. In this work, Co/C nanocomposites are prepared by a vacuum-assisted impregnation and carbothermic reduction process. Carbon matrix has porous honeycomb-like microstructure coming from the wood precursor, the cobalt nanoparticles are uniformly distributed on the wall of porous carbon matrix. The optimal microwave-absorption is achieved with a minimum RL of -49.8 dB at 9.4 GHz, matched with a thin thickness of 1.5 mm, and its effective microwave-absorption covers a wide frequency range by changing the thickness of the sample, from 4.8 to 11.2 GHz and from 11.4 to 18 GHz. The excellent absorption performance of Co/C nanocomposites is mainly attributed to good impedance matching and moderate attenuation factor, which is realized by dielectric relaxation. This work demonstrates a simple method for synthesizing high-performance microwave-absorbing nanocomposites by biomass conversion. 

Excellent Microwave Absorption Performance in Porous Co/C Nanocomposites by Biomass Conversion