CoFe2O4/N-doped reduced graphene oxide aerogels for high-performance microwave absorption

Nowadays, to solve electromagnetic radiation issues, an urgent demand is to develop high-performance microwave wave absorption materials with lightweight, broad bandwidth and strong absorbing capacity. In this work, by embedding CoFe2O4 (CFO) nanoparticle into N-doped reduced graphene oxide (N-rGO) aerogels, a unique CFO/N-rGO aerogel microwave wave absorber with a 3D porous architecture is synthesized via a facile solvothermal method and lyophilization technique. Impressively, the as-synthesized N-rGO aerogels exhibit typical ferromagnetic behavior. The electromagnetic parameters of CFO/N-rGO aerogels can be immensely improved by tuning the additive amount of CoFe2O4 nanoparticle. An optimal microwave absorption performance is achieved when the mass ratio of graphene oxide (GO) to CoFe2O4 is 1:2. Here, a strong reflection loss (RL) reaches -60.4 dB at 14.4 GHz with a thickness of 2.1 mm and a low filler loading ratio of 20 wt%. Further, the effective absorption bandwidth (RL < -10 dB) can be up to 6.48 GHz (11.44-17.92 GHz) with a thickness of 2.2 mm. Notably, at only 3 mm, its effective absorption bandwidth can completely cover X-band. The superior microwave wave absorption performance of as-synthesized CFO/N-rGO aerogels is attributed to the specific surface morphology and porous structures, leading to the multiple scattering and reflecting, interfacial polarization and optimal impedance matching. This work not only provides a deep insight on tuning microwave absorption performance of ferrite/N-rGO aerogels, but also offers a new route to design high-performance magnetic/dielectric absorbers.