A 3D multifunctional nitrogen-doped RGO-based aerogel with silver nanowires assisted self-supporting networks for enhanced electromagnetic wave absorption

Abstract

We designed a promising three-dimensional (3D) nitrogen-doped reduced graphene oxide-based aerogel (NGA) with silver nanowires (Ag NWs) assisted self-supporting networks for enhanced electromagnetic wave (EMW) absorption. 3D AgNWs@NGAs (8–12 mg/mL) were synthesized by a three-step strategy of sonication, reduction, and lyophilization. The results show that introduced sp3 defects and disordered sites in nitrogen doping from a rarely-reported liquid nitrogen source of acetonitrile remarkably improved electronic dipole polarization relaxation and EMW absorption ability. Besides, electronic band structure and density of states of the NGA were investigated by first-principles calculations to indicate that the carrier mobility became smaller during nitrogen doping. The Ag NWs were distributed on an NGA as the 3D network structure of an elastic support and a conductive and compatible unit, which limited the aggregation of NGA flakes, and further strengthened conductive loss. Significantly, the synthesized ultralight AgNWs@NGA exhibits excellent performance at 9.52 GHz, with a strong minimal reflection loss of –79.99 dB, a small thickness of 2.660 mm, a wide effective absorption bandwidth of 3.5 GHz, and an ultra-low filler content of 5 wt%. Furthermore, a large specific surface of 331.5 cm3/g, a good conductivity of approximately 50 S/cm, a high resilience, and an excellent heat insulation capability, guarantee the durable stability in EMW absorption of AgNWs@NGAs to resist distortion and heat attacks.