Understanding the microstructure-property relationship from the microscopic and macroscopic perspectives,instead of semi-empirical rules,can facilitate the design of microcosmic morphology to adjust the impedance matc...Understanding the microstructure-property relationship from the microscopic and macroscopic perspectives,instead of semi-empirical rules,can facilitate the design of microcosmic morphology to adjust the impedance matching and dielectric loss of the carbon-based materials,which are still lacking so far.In this study,a clear correlation between microstructure and conduction loss was revealed in agarosederived carbon using a facile salt-etching strategy,in which ferric nitrate acted more as a morphology modifier for bulky carbon rather than a component regulator.Specifically,with the increasing amount of ferric nitrate,the original smooth bulky carbon was etched with caves,which gradually enlarged in size and depth and thus thinned in wall,and eventually transformed into a three-dimensional(3D)interconnected cellular structure,accompanied by a gradual increase in conductivity.Benefiting from the optimal impedance matching and strong conduction loss originating from the unique 3D cellular structure of agarose-derived carbon,AF-3 exhibited super-wide and strong absorption with an effective absorption bandwidth of 7.28 GHz(10.32-17.60 GHz,2.9 mm)and a minimum reflection loss of-46.6 dB(15.6 GHz,2.5 mm).This study establishes the relationship between microstructure,dielectric properties,and loss mechanism in carbon-based materials and also provides a new insight into the fine modulation of EMW-absorbing properties from morphological design.展开更多
基金supported by the National Natural Science Foundation of China(No.52362024 and 22004106).
文摘Understanding the microstructure-property relationship from the microscopic and macroscopic perspectives,instead of semi-empirical rules,can facilitate the design of microcosmic morphology to adjust the impedance matching and dielectric loss of the carbon-based materials,which are still lacking so far.In this study,a clear correlation between microstructure and conduction loss was revealed in agarosederived carbon using a facile salt-etching strategy,in which ferric nitrate acted more as a morphology modifier for bulky carbon rather than a component regulator.Specifically,with the increasing amount of ferric nitrate,the original smooth bulky carbon was etched with caves,which gradually enlarged in size and depth and thus thinned in wall,and eventually transformed into a three-dimensional(3D)interconnected cellular structure,accompanied by a gradual increase in conductivity.Benefiting from the optimal impedance matching and strong conduction loss originating from the unique 3D cellular structure of agarose-derived carbon,AF-3 exhibited super-wide and strong absorption with an effective absorption bandwidth of 7.28 GHz(10.32-17.60 GHz,2.9 mm)and a minimum reflection loss of-46.6 dB(15.6 GHz,2.5 mm).This study establishes the relationship between microstructure,dielectric properties,and loss mechanism in carbon-based materials and also provides a new insight into the fine modulation of EMW-absorbing properties from morphological design.
