Abstract
Graphene aerogels possessing a three-dimensional (3D) porous netlike structure, good electrical conductivity and ultralow density have been widely regarded as a promising candidate for high-efficiency electromagnetic wave (EMW) absorption. Herein, nitrogen-doped reduced graphene oxide/cobalt-zinc ferrite (NRGO/Co0.5Zn0.5Fe2O4) composite aerogels were synthesized through a solvothermal and subsequent hydrothermal self-assembly two-step method. The results of micromorphology analysis showed that the 3D networks were well constructed through the partial stacking of adjacent NRGO sheets, which were decorated with numerous Co0.5Zn0.5Fe2O4 microspheres. The as-synthesized NRGO/Co0.5Zn0.5Fe2O4 composite aerogels have a very low density (12.1-14.6 mg cm-3) and good compression recovery. Moreover, excellent EMW absorption performance could be achieved through facilely regulating the additive volume of ethylenediamine (i.e. nitrogen doping contents) and filler contents. Impressively, the composite aerogel with a doped nitrogen content of 2.5 wt% displayed the optimal minimum reflection loss (RLmin) of -66.8 dB in the X-band at a thickness of 2.6 mm and the broadest effective absorption bandwidth of 5.0 GHz under an ultrathin thickness of merely 1.6 mm. Meanwhile, the RLmin of NRGO/Co0.5Zn0.5Fe2O4 composite aerogels below -20 dB could be reached in almost the whole tested thickness range (1.4-5.0 mm). Additionally, the potential EMW absorption mechanisms were revealed, which was mainly due to the unique 3D porous netlike structure, synergistic effects among conduction loss, magnetic resonance loss and polarization loss, as well as the balanced attenuation capacity and impedance matching. It was believed that this work provided an alternative way for fabricating strong mechanical graphene-based 3D magnetic/dielectric composites as light-weight and high-efficiency EMW absorbers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
