▎ 摘　　要

Graphene quantum dots interfacial-decorated hierarchical Ni/PS core/shell nanocapsules were successfully synthesized by three-step liquid chemical method. The morphologies and electromagnetic properties were carefully studied in order to investigate the dielectric shells modulated tunable microwave absorption in 1-18 GHz (L-Ku), based on the anisotropic nanoflakes assembled magnetic core. With different GQDs/PS ratio in the shells, the dielectric attenuation can be flexibly tuned by the interfacial polarizations deriving from the density modulation of interfacial-decorated polar GQDs in the nonpolar insulative PS matrix. The calculated impedance matching maps, microwave absorption efficiencies (R-E), reflection loss (RL) and simulations illustrated the coincident effect with an obvious rise-fall performance in X-Ku band. The tunable RL value in fixed frequency of X band and shifting absorption peaks from Ku to X band were achieved in different absorber thickness with the minimum RL below -42.5 dB and the effective absorption bandwidth (RL < -10 dB) above 2.04 GHz. (C) 2020 Elsevier B.V. All rights reserved.