Facile fabrication of lightweight and three-dimensional porous Dy2O3 decorated single-walled carbon nanotubes/reduced graphene oxide composite aerogels for broadband microwave absorption

Abstract

Reduced graphene oxide aerogel (GA) has emerged as a promising microwave absorbing (MA) material. However, it remains a challenge for pure GA to achieve excellent MA performance owing to the limitation of loss model and impedance mismatching. Herein, a 0D@1D/2D construction of Dy₂O₃ decorated single-walled carbon nanotubes/reduced graphene oxide (Dy₂O₃@SWCNT/rGO) composite aerogel (DCGA) with high-performance electromagnetic wave (EMW) absorption was successfully obtained using a simple reduction self-assembly process. The DCGA features a distinctive 3D porous network formed by the stacking of lamellar rGO and has a low bulk density. As expected, the microwave attenuation performance of the DCGA exhibits a level of tunability that can be achieved by varying the mass ratio of GO along with Dy₂O₃@SWCNT. Benefiting from synergistic effect, the resulted ultralight DCGA-3 (4.6 mg/cm⁻³) exhibits a strong reflection loss (RL) of −57.6 dB (3 mm) at 13 GHz and a low filler loading ratio of ca. 1.4 wt%. Further, the maximal effective absorption bandwidth (EAB) (RL < −10 dB) of DCGA-1 can reach 7.8 GHz (10.2–18 GHz) with a thickness of 2.8 mm. Notably, the EAB of DCGA can completely cover X band and Ku band by adjusting the thickness. The excellent EMW absorbing ability was originated from the combined influence of optimized impedance matching, a distinctive multidimensional porous structure, a leaf-like conductive network and the presence of numerous defects and interfaces. Consequently, this research may aid in the development of graphene-infused hybrid composites featuring a 3D porous architecture, serving as lightweight and efficient absorbers of EMWs.