Developing lightweight and broadband microwave absorbers for dealing with serious electromagnetic radiation pollution is a great challenge.Here,a novel Fe-Co/N-doped carbon/reduced graphene oxide(Fe-Co/NC/rGO)composit...Developing lightweight and broadband microwave absorbers for dealing with serious electromagnetic radiation pollution is a great challenge.Here,a novel Fe-Co/N-doped carbon/reduced graphene oxide(Fe-Co/NC/rGO)composite with hierarchically porous structure was designed and synthetized by in situ growth of Fe-doped Cobased metal organic frameworks(Co-MOF)on the sheets of porous cocoon-like rGO followed by calcination.The Fe-Co/NC composites are homogeneously distributed on the sheets of porous rGO.The Fe-Co/NC/rGO composite with multiple components(Fe/Co/NC/rGO)causes magnetic loss,dielectric loss,resistance loss,interfacial polarization,and good impedance matching.The hierarchically porous structure of the Fe-Co/NC/rGO enhances the multiple reflections and scattering of microwaves.Compared with the Co/NC and Fe-Co/NC,the hierarchically porous Fe-Co/NC/rGO composite exhibits much better microwave absorption performances due to the rational composition and porous structural design.Its minimum reflection loss(RLmin)reaches?43.26 dB at 11.28 GHz with a thickness of 2.5 mm,and the effective absorption frequency(RL≤?10 dB)is up to 9.12 GHz(8.88-18 GHz)with the same thickness of 2.5 mm.Moreover,the widest effective bandwidth of 9.29 GHz occurs at a thickness of 2.63 mm.This work provides a lightweight and broadband microwave absorbing material while offering a new idea to design excellent microwave absorbers with multicomponent and hierarchically porous structures.展开更多
基金the National Natural Science Foundation of China(No.21376029)and the Analysis&Testing Center,Beijing Institute of Technology for sponsoring this researchsupported by Beijing Key Laboratory for Chemical Power Source and Green Catalysis,Beijing Institute of Technology.
文摘Developing lightweight and broadband microwave absorbers for dealing with serious electromagnetic radiation pollution is a great challenge.Here,a novel Fe-Co/N-doped carbon/reduced graphene oxide(Fe-Co/NC/rGO)composite with hierarchically porous structure was designed and synthetized by in situ growth of Fe-doped Cobased metal organic frameworks(Co-MOF)on the sheets of porous cocoon-like rGO followed by calcination.The Fe-Co/NC composites are homogeneously distributed on the sheets of porous rGO.The Fe-Co/NC/rGO composite with multiple components(Fe/Co/NC/rGO)causes magnetic loss,dielectric loss,resistance loss,interfacial polarization,and good impedance matching.The hierarchically porous structure of the Fe-Co/NC/rGO enhances the multiple reflections and scattering of microwaves.Compared with the Co/NC and Fe-Co/NC,the hierarchically porous Fe-Co/NC/rGO composite exhibits much better microwave absorption performances due to the rational composition and porous structural design.Its minimum reflection loss(RLmin)reaches?43.26 dB at 11.28 GHz with a thickness of 2.5 mm,and the effective absorption frequency(RL≤?10 dB)is up to 9.12 GHz(8.88-18 GHz)with the same thickness of 2.5 mm.Moreover,the widest effective bandwidth of 9.29 GHz occurs at a thickness of 2.63 mm.This work provides a lightweight and broadband microwave absorbing material while offering a new idea to design excellent microwave absorbers with multicomponent and hierarchically porous structures.
