Honeycomb-like Co/C composites derived from hierarchically nanoporous ZIF-67 as a lightweight and highly efficient microwave absorber

By Lei Wang, Xiaoyun Bai, Bo Wen, Du Zhen, Ying Lin. Composites Part B: Engineering, 2019

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Abstract A simple method synthesizing hierarchically porous Co-based zeolitic imidazolate frameworks (ZIF-67) is presented. In approach, polyvinyl pyrrolidone (PVP) aggregates on graphene oxide (GO) surface through H-bond between oxygen-containing groups ( OH and COOH) on GO and C O in PVP and the results GO/PVP composites is used as a template to synthesize hierarchically porous ZIF-67. After in situ postpyrolysis heat treatment in Ar atmosphere, honeycomb-like Co/C composites with abundant hierarchically pores are obtained. The hierarchically porous structure endows the as-obtained Co/C composites with highly efficient microwave absorption performances. The maximum reflection loss can reach −50.7 dB and the effective bandwidth is 4.6 GHz at a filler loading as low as 10 wt%. Notably, the electromagnetic parameters analysis indicates that such excellent microwave absorption properties are mainly ascribed to well-matched impedance combined with strong attenuation property induced by the hierarchically porous structure. More importantly, this strategy could also be used to fabricate other MOF-derived high performance microwave absorbers.

Subfields: Aerospace Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/6a1a4a01404315d12e6832f075d7423c2c248438