Structure engineering of 3D interconnect graphene nanocapsules for microwave absorption

Abstract

Constructing porous structures is important for enhancing the impedance matching of carbon-based microwave absorbing materials (MAM) and achieving effective electromagnetic wave absorption. In this study, we prepared three-dimensional interconnected graphene nanocapsules (IGNCs) with a honeycomb-like structure using trisodium citrate dihydrate. During pyrolysis, sodium citrate dihydrate undergoes self-assembly and thermal polymerization, forming interconnected nanocapsules. The homogeneous distribution of Na2CO3 serves as a template for this process. The IGNCs-700 demonstrated an effective absorption bandwidth (EAB) of 4.32 GHz, at a fill concentration of only 5 wt.% and a matched thickness of 2.3 mm. Finally, Computer Simulation Technology (CST) simulation results further validate the radar microwave absorption capability of the IGNCs-700 under far-field conditions.