A novel multi-cavity structured MOF derivative/porous graphene hybrid for high performance microwave absorption

Carbon materials exhibit potential as lightweight microwave absorption (MA) absorber, however, the MA performance of them is strongly limited due to the single loss mode and unsatisfactory spatial topography. In this work, the novel porous ZnO/ZnFe2O4/C@PG composites are synthesized using metal organic framework (MOF) and micro-sized porous graphene (PG) network as precursors via a synchronous reflux strategy for sufficient MA performance. As multi-component composites, the component of ZnO/ZnFe2O4/C will provide excellent dielectric loss and certain magnetic loss, while the PG conductive network can create more electronic transmission paths and significant conductive loss. In addition, the unique porous structure increases the probability of multiple reflection and scattering, which contributes to the high MA ability of ZnO/ZnFe2O4/C@PG. The minimum reflection loss (RL) value of ZnO/ZnFe2O4/C@PG could reach −54.6 dB at frequency of 9.04 GHz with thickness of 2.7 mm，and the effective absorption bandwidth (RL ≤ −10 dB, EAB) covered as wide as 5.36 GHz. This result demonstrates that ZnO/ZnFe2O4/C@PG composites have promising potential as tunable, broadband and high-performance microwave absorber. [Display omitted]