图1 纳米电磁波吸收材料的分类及机理

Fig. 1 Categorization and mechanisms of nanoscale electromagnetic wave-absorption materials

图2 电磁波入射到介质表面发生的反射、吸收和透过三种相互作用

Fig. 2 Three interactions occurring when electromagnetic waves are incident on the surface of medium: reflection, absorption, and transmission

图3 微纳结构与电磁性能的构效关系

Fig. 3 Structure-property relationship of micro-nanostructures and electromagnetic performance

图4 元素掺杂策略调控材料电子状态

Fig. 4 Element doping strategy for regulating material electron states (a) Various metal ion-doped perovskite quantum dots at the B-site cation enhancing their thermal stability and phase stability[80]; (b) Sr2+ doping reducing the surface trap density and charge recombination in quantum dots[84]; (c) Defects within the material structure and strong polarization at heterojunction interfaces showing outstanding electromagnetic wave absorption performance[85]; (d) Nitrogen element doping in carbon quantum dots improving their internal heterogeneous charge distribution[20]

图5 表面效应策略调控电子状态

Fig. 5 Surface effect strategy for regulating electron states (a) Capturing electrons at lower temperature with deep defect levels[89]; (b) Equivalent circuits of graphene coatings with low- and high-concentration defects[90]; (c) Impact of surface ligand on the crystal phase, exciton recombination and charge carrier mobility of quantum dots[91]

图6 成核生长控制策略调控电子状态

Fig. 6 Nucleation-growth control strategy for regulating electron states (a) Synthetizing carbon quantum dots with different quantum efficiencies by controlling the reaction temperature[92]; (b) Tuning bandgap by controlling the reaction temperature[93]; (c) Generating carbon quantum dots with adjustable bandgaps in different polar solvent environments[94]

图7 量子点在吸波领域的应用

Fig. 7 Application of quantum dots in the field of electromagnetic wave absorption (a) High-efficiency electromagnetic wave absorption mechanism of Na2Ti3O7/MXene quantum dot composite material[100]; (b) One-, two-, and three-dimensional absorption performances of Na2Ti3O7/MXene quantum dot composite material[100]; (c) Reflection loss values of ZnFe2O4 quantum dot composite material at different thicknesses[103]; (d) Schematic illustration of mechanisms for ZnFe2O4 quantum dot polycrystalline inversion and electromagnetic microwave absorption[103]

图8 纳米晶在吸波领域的应用

Fig. 8 Application of nanocrystals in the field of electromagnetic wave absorption (a) Schematic typical synergistic mechanism on relationship between magnetic loss of FeNi3 nanocrystals and dielectric loss of graphene nanosheets[110]; (b) Enhanced electromagnetic loss facilitated by promoted interfacial polarization using ZnO nanocrystals[111]; (c) Charge separation-induced polarization loss in Fe3O4 nanocrystals through surface oxygen vacancy defects[112]; (d) Three-dimensional absorption performance of Fe3O4 nanocrystal composite at different annealing temperatures[112]

图9 纳米线在吸波领域的应用

Fig. 9 Application of nanowires in the field of electromagnetic wave absorption (a) Schematic mechanisms of various loss including interface polarization, dipole polarization, and their related relaxation activated by Ag nanowires[119]; (b) First-principles confirmation of efficient electromagnetic wave absorption which resulted from conductivity loss generated by a three-dimensional network structure formed with carbon nanotubes and polarization loss induced by Sc2Si2O7[69]