Hierarchical interface-engineered magnetic graphene-sicn aerogels via stepwise confinement strategy for low-frequency and broadband microwave absorption

The rapid advancement of artificial intelligence, 5G communication, and the Internet of Things has propelled society into an era dominated by high-frequency electromagnetic signals. These technologies, while revolutionizing information transmission and interconnectivity across diverse fields such as communication, energy, and healthcare, have also led to an unprecedented surge in electromagnetic wave (EMW) radiation. Excessive EMW exposure not only interferes with the reliable operation of sensitive electronic equipment but also poses potential risks to human health. Meanwhile, in the defense sector, the growing importance of electromagnetic stealth has driven demand for materials capable of effectively attenuating stray electromagnetic radiation. To meet the growing demand for efficient EMW management, extensive research has been devoted to the development of high-performance EMW absorbing materials. Among various candidates, carbon-based materials—such as carbon nanotubes, carbon nanofibers, and graphene—have garnered significant attention due to their low density, tunable electrical conductivity, and chemical stability. In particular, reduced graphene oxide (rGO) with a large specific surface area and abundant defect sites, exhibits great promise in EMW absorption. When assembled into aerogel architectures, rGO not only inherits these intrinsic advantages but also gains a hierarchically porous network characterized by ultralow density and continuous conductive pathways. This unique structure enables multiple internal scattering, prolonged transmission paths, and improved impedance matching, positioning rGO aerogels (GA) as a highly attractive platform for lightweight and broadband EMW absorption systems. Despite their structural advantages, rGO aerogels still face significant challenges in achieving both strong low-frequency absorption and broad effective bandwidth.

Recently, a team of material scientists led by Xiaogu Huang from Nanjing University of Information Science and Technology University, reported a new hierarchical heterogeneous interface engineering strategy to realize synergistic low-frequency and broadband microwave absorption in lightweight magnetic graphene-SiCN aerogels. By stepwise confining ZIF-67 nanoparticles and a polysilazane-derived SiCN nanolayer onto a graphene aerogel framework, multiscale 0D-2D and 2D-2D heterointerfaces were successfully constructed. These engineered interfaces significantly enhanced interfacial polarization, dipolar relaxation, and magnetic–dielectric synergistic loss, leading to a minimum reflection loss of −60.63 dB at 5.52 GHz and a broad effective absorption bandwidth of 7.89 GHz at a thickness of only 2.4 mm. This work provides a new design strategy for next-generation lightweight low-frequency electromagnetic wave absorbing materials.

The team published their work in Journal of Advanced Ceramics on October 4, 2025.

“In this study, a hierarchical heterogeneous interface engineering was proposed to elucidate the underlying mechanisms by which interfacial modulation governs EMW absorption performance. Taking rGO aerogel as the structural framework, a lightweight porous rGO@ZIF-67@polysilazane/ZIF-67 (GMSM)-derived magnetic graphene-SiCN aerogel with a density of 72.7 mg cm-3 was successfully fabricated via a stepwise confinement strategy.” said Xiaogu Huang, professor at Nanjing University of Information Science and Technology University (China), a senior expert whose research interests focus on the field of electromagnetic wave absorption material.

“This process involved the in situ crystallization of ZIF-67, impregnation with a polysilazane nanolayer embedding ZIF-67 onto the rGO framework, and subsequent confined pyrolysis. The pyrolysis of ZIF-67 generated Co/CoO nanoparticles uniformly anchored onto the rGO framework, thereby constructing 2D-0D heterointerfaces that induced natural resonance and eddy current dissipation. Upon the subsequent incorporation of a conformal SiCN ceramic layer, integrated 2D-0D-2D hierarchical interfaces were established.” said Xiaogu Huang.

GMSM-800 composite achieved a minimum reflection loss of −60.63 dB at a low frequency of 5.52 GHz and a maximum effective absorption bandwidth of 7.89 GHz at a reduced matching thickness of only 2.4 mm, demonstrating considerable promise for next-generation high-performance EMW absorbing materials. “The rationally designed hierarchical heterostructure promotes strong interfacial polarization and synergistic dipolar/defect relaxation, simultaneously optimizing low-frequency impedance and inducing dual reflection-loss minima, thereby achieving both pronounced low-frequency EMW absorption and an extended effective bandwidth” said Xiaogu Huang.

Other contributors include Gaoyuan Yu, Gaofeng Shao, Zhilong Xu and Yu Chen from the Nanjing University of Information Science and Technology University in Nangjing, China.

This work was supported by the National Natural Science Foundation of China (52573327, 62071239, 52102361), 333 High-Level Talents Cultivation Project of Jiangsu Province (BRA2022094), Young Elite Scientists Sponsorship Program by Jiangsu Association for Science and Technology (JSTJ2023XH047), China Postdoctoral Science Foundation (2022 M721669, 2025T180037).

About Author

Xiaogu Huang, Professor and Doctoral Supervisor, School of Chemistry and Materials Science, Nanjing University of Information Science and Technology, China.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/33, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508