Carbon-based cages with hollow confined structures for efficient microwave absorption: State of the art and prospects

The design of lightweight and efficient electromagnetic wave absorbing materials (EWAMs) is of great signifi-cance in the fields of information security and the target stealth. Recently, hollow carbon-based confined structures have been widely concerned due to some unique characteristics of the electromagnetic wave ab-sorption process. First, Hollow structures with resonant cavity characteristics facilitate electromagnetic wave scattering and endow structures with multimode resonance properties. Second, a hollow structure is beneficial to reduce its bulk density and complex permittivity, and its unique confined structure can be used as a storehouse for storing air to optimize the impedance matching characteristics of the EWAM. In this paper, the recent research progress on carbon-based hollow EWAMs has been profoundly reviewed, including the categories of pure carbon EWAMs and carbon-based composites, design strategies, synthetic methods, and the structure -function relationship of EWAMs. Finally, the challenges, and prospects for practical applications of hollow carbon-based structures are also discussed. We believe that this critical review is timely and not only highlights the recent advances and advantages of the carbon-based EWAMs, but also inspires new concepts for designing hollow-structure absorbers.

Automated summary

The design of lightweight and efficient electromagnetic wave absorbing materials (EWAMs) is crucial for information security and target stealth. Hollow carbon-based confined structures have garnered attention due to their unique electromagnetic wave absorption characteristics. This paper reviews the recent progress on carbon-based hollow EWAMs, covering pure carbon materials, carbon-based composites, design strategies, synthetic methods, and the structure-function relationship of EWAMs. The challenges and prospects for practical applications of hollow carbon-based structures are also discussed.