2-Methylimidazole-mediated hierarchical Co3O4/N-doped carbon/short-carbon-fiber composite as high-performance electromagnetic wave absorber

Zehao Zhao; Kaichang Kou; Hongjing Wu

doi:10.1016/j.jcis.2020.04.037

2-Methylimidazole-mediated hierarchical Co₃O₄/N-doped carbon/short-carbon-fiber composite as high-performance electromagnetic wave absorber

J Colloid Interface Sci. 2020 Aug 15:574:1-10. doi: 10.1016/j.jcis.2020.04.037. Epub 2020 Apr 9.

Authors

Zehao Zhao¹, Kaichang Kou², Hongjing Wu³

Affiliations

¹ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China; MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
² MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
³ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China. Electronic address: wuhongjing@mail.nwpu.edu.cn.

PMID: 32298976
DOI: 10.1016/j.jcis.2020.04.037

Abstract

At present, efficient and stable low-cost electromagnetic (EM) wave absorbing materials have been widely explored, but further improvement is still necessary. In this research, three types of hierarchical Co₃O₄/N-doped carbon/short carbon fiber (SCF) composites with different assembly structures were produced by annealing the ZIF-67/SCF and Co-LDHs/SCF precursors at 700 °C. The obtained Co₃O₄/N-doped carbon particles were uniformly attached on SCF in the form of nanocages or thin layer to compose a unique hierarchical structure. Notably, all three composites displayed high-performance EM wave absorption with a low filling ratio of only 20 wt% in paraffin matrix. Among them, cage-like Co-LDHs/SCF derived hierarchical carbon composite demonstrates the best performance, with a broad absorption bandwidth (RL ≤ -10 dB) of 6.08 GHz at 2.0 mm. Such excellent properties are attributed to the formed 3D conductive network, abundant Debye dipolar relaxation centers and strong interfacial polarization. These novel lightweight 2-methylimidazole-mediated Co₃O₄/N-doped carbon/SCF composites are expected to show great potential in EM wave absorption fields.

Keywords: Electromagnetic wave absorption; Interfacial polarization; Layered double hydroxide; ZIF-67.