Ultrasmall SnFe2O4 nanoparticles anchored on N-doped carbon nanofibers for ultralight and high-performance microwave absorption

One-dimensional (1D) N-doped carbon nanofibers decorated with ultrafine (similar to 4.5 nm) SnFe2O4 nanoparticles (denoted as SFO/N-CNFs) are successfully synthesized by a combination of electrospinning and solvothermal process, and their microwave absorption (MA) properties are reported for the first time. With only 5 wt% filler loading in a silicone rubber matrix, the optimum reflection loss (RL) could reach -46.5 dB and the qualified frequency bandwidth (RL < -10 dB) can be capable of 4.8 GHz at 1.6 mm, exhibiting better comprehensive absorption performance relative to other analogous absorbers. The lightweight and highly efficient MA of SFO/N-CNFs is largely ascribed to the improved impedance matching and satisfactory attenuation ability caused by the synergistic effect between the ultrasmall-sized SFO nanoparticles (NPs) and 1D N-CNF matrix. This work not only offers a novel and promising high-performance microwave absorber, but also offers a general approach to designing and fabricating ultrasmall transition metal oxide nanoparticle decorated carbon-based composite nanostructures for multifunctional applications.