Polarization genes dominated heteroatom-doped graphene aerogels toward super-efficiency microwave absorption

Abstract

Dielectric gene regulation has already been regarded as an effective strategy to manipulate the electromagnetic wave response of two-dimensional graphene-based absorbers. However, there is still a lack of elaborate understanding and precise tailoring of dielectric genes inside three-dimensional graphene aerogels. Herein, ultralight heteroatom (N, S)-doped graphene aerogels (NSGAs) were achieved via the thermolysis of pyrrole and thiourea molecule cross-linked graphene aerogels. The cellular structure of NSGA improves the impedance matching, and the heteroatom-doped cell walls generate a great quantity of dipolar and defect polarization sites, synergistically promoting its microwave attenuation. The optimal NSGA exhibits a minimal reflection loss (RL_min) of −67.64 dB (99.99998% wave absorption) at a relatively low thickness of 2.0 mm and a maximum efficient absorption bandwidth of 6.12 GHz with an ultralow filler ratio of 0.45 wt%. Meanwhile, NSGA displays a remarkable specific reflection loss (|RL_min|/filler ratio) of 15031 dB and specific microwave absorption performance (SMAP, |RL_min|/(thickness × density)) of 82 892 dB cm² g⁻¹, superior to most graphene aerogel-based absorbers. This work provides an effective heteroatom-doping strategy to regulate polarization genes of graphene aerogels for super-efficiency microwave absorption with the integrated features of “thin, ultralight, strong, and broadband”.