Fabrication of graphene/polyimide/Co-N-C aerogel with reinforced electromagnetic losses and broadband absorption for highly efficient microwave absorption and thermal insulation

The fabrication of dielectric/magnetic multicomponent hybrids represents a promising strategy for achieving advanced electromagnetic wave (EMW) absorption performances. However, it also poses a significant challenge due to the difficulty in fully utilizing the properties of each component. Here, in this work, metal–organic frameworks (MOFs) derived Co-N-C species were combined with graphene oxide/polyamide acid and then freeze-dried and annealed to produce PI/rGO/CNC aerogels. These aerogels exhibit outstanding EMW absorption properties owing to their multiple heterogeneous interfaces and synergetic electromagnetic losses while retaining satisfying mechanical properties and lightweight features of PI/rGO aerogels. In particular, PI/rGO/CNC-1 aerogel shows the optimal EMW attenuation performance with a minimal reflection loss (RLmin) value of –75 dB, and its maximal effective absorption bandwidth (EABmax) is as broad as 7.28 GHz. Moreover, the lightweight nature, elastic feature, structural stability, thermal insulation and hydrophobicity of the PI/rGO/CNC aerogels ensure that they have vast application prospects as advanced EMW absorption materials in complicated environment.