Three-dimensional porous, flexible and lightweight reduced graphene oxide/Li0.35Zn0.3Fe2.35O4@SiO2 nanofibers aerogel for efficient microwave absorption

Abstract

The development of flexible, lightweight, broadband EMW-absorbing materials is necessary for individual protection. However, balancing the mechanical properties and high absorbent performance of aerogel materials is challenging. We hypothesized that lightweight RGO/LZFO@SiO2 NFs flexible composite aerogels with three-dimensional (3D) porosity, flexibility and a high absorption capacity could be prepared via a simple preparation strategy combining electrospinning, freeze-drying, and heat curing. First, flexible LZFO@SiO2 NFs were prepared via sol–gel electrospinning, whereby LZFO particles were embedded in the SiO2 NFs. Subsequently, the LZFO@SiO2 NFs and graphene oxide (GO) were homogenized in deionized water with the addition of a crosslinker along with vigorous stirring. Finally, aerogels with cross-linked structures were obtained after freeze-drying and calcination treatments. Under 30% strain, the stress undergone by RGO/LZFO@SiO2 NFs-2 reached 32 kPa. After 200 anti-fatigue tests, the plastic deformation was 15%. The combined action of the RGO conductive elements and LZFO@SiO2 NFs magnetic elements cooperate to improved the impedance-matching imbalance, and the two were bonded to produce form a rich interface effect. The RGO/LZFO@SiO2 NFs-2 aerogel exhibited a minimum reflection loss (RLmin) of −55.1 dB (2.2 mm) and an effective absorption bandwidth (EAB) of 4.3 GHz.