Construction of three-dimensional holey/magnetic Co graphene aerogel for lightweight and broadband microwave absorption

Three-dimensional graphene aerogels are emerging as promising materials for microwave absorption, due to their unique characteristics of low density and high porosity. Although lightweight electromagnetic wave (EMW) graphene-based aerogel absorbers have been developed, synergistically optimizing the EMW performance of these absorbers through structural design and simultaneously introducing multiple loss mechanisms remains challenging. This paper presents an innovative design strategy that modifies the hole structure of aerogel by controlling the content of Co ions while simultaneously introducing magnetic loss, thereby achieving ultra-light broadband absorption performance. Notably, when the added amount of Co ions is 0.3 mmol, the aerogel exhibits a minimum reflection loss (RLmin) of -44.9 dB, and an effective absorption bandwidth (EAB) of 5.68 GHz. The remarkable EMW absorption performance can be attributed to the enhancements of polarization loss and magnetic loss. Furthermore, the RCS simulation results indicate that the aerogel effectively reduces EMW scattering in practical applications. Thus, this research offers a highly effective strategy for the development of EMW absorption materials that are thin, lightweight, broadband, and high-performance.