Dual heteroatoms co-doping strategy of graphene-based dielectric loss electromagnetic absorbent

Abstract

In this paper, the modulation of microwave absorption performance through diatomic co-doping was systematically investigated. N, S co-doped reduced graphene oxide (NS-rGO) and S, B co-doped rGO (SB-rGO) were obtained by one-pot hydrothermal reaction and freeze-drying. The experimental results and theoretical calculations suggested that the charge distribution of N, B and S heteroatoms with adjacent C atoms obviously changed, which effectively regulated the electronic transmission and polarization state, and accordingly affected the dielectric response. Besides, compared to N-rGO and B-rGO, impedance matching characteristics and electromagnetic attenuating capability of NS-rGO and SB-rGO were significantly enhanced due to the synergistic regulation of pyrrolic N, pyridinic N, -CBO2-, B-C3 and -C-SO2-C- bonds. NS-rGO exhibited the minimum reflection loss (RLmin) of −52 dB at 10 GHz under an ultra-low loading of 2 wt%, and its effective absorption bandwidth (EAB, below −10 dB) ranged from 7 GHz to 18 GHz in the thickness of 2.0–3.8 mm. SB-rGO also exhibited the RLmin of −54.2 dB at 11.8 GHz under an ultra-low loading of only 1.5 wt%, and the EAB of 12 GHz (6–18 GHz) in the thickness of 2.0–3.8 mm. This work offers a deep insight into the relationship among dual atoms co-doping, dielectric performance and microwave absorption property.