ZIF-67-derived micron-sized cobalt-doped porous carbon-based microwave absorbers with g-C3N4 as template

Porous carbon-based materials have been widely used in microwave absorption due to their light weight and special structure. In this work, a newly Co-doped porous micron-sized carbon-based microwave absorber was successfully prepared via a template method, in which g-C3N4 was used as a template to gather ZIF-67 on its surface. As-synthesized MOF-derived composites retained the aggregation state of MOF in the precursor, and possessed porous structure originating from the carbonization and decomposition of ZIF-67. With the increased addition of g-C3N4, MOF-derived composites exhibited decreased permittivity and raised permeability resulting in an improved impedance match. For CN/CCo-500 sample, the optimal reflection loss was −37.21 dB at 12.22 GHz with a given thickness of 2.6 mm, while the corresponding effective absorption bandwidth covered the range from 10.25 GHz to 16.7 GHz. As-prepared porous composite with light density and broadband microwave absorption performance could be a promising candidate in electromagnetic wave absorption application.