Construction of tunable and high-efficiency microwave absorber enabled by growing flower-like TiO2 on the surface of SiC/C nanofibers

Flower branch-like TiO2@SiC/C composite nanofibers that are lightweight and have high-efficiency microwave absorption (MA) in the 2-18 GHz frequency range were fabricated via electrospinning and hydrothermal approaches. Phase analysis results showed the presence of rutile TiO2, 'beta-SiC, and amorphous carbon in the composite nanofibers. Nanowhiskers grew randomly on the surface of the nanofibers along the (101) plane of rutile TiO2 nanocrystalline and formed a flower branch-like structure. The bionic morphology generated a great deal of heterojunctions and porous structures, which enable interfacial polarization, dipole polarization, conductance loss, multirelaxation, and suitable impedance matching through synergistic effects. Therefore, excellent wave-absorbing performance was achieved in the X and Ku bands when the composite nanofibers' filler loading was changed. The minimum reflection loss (RL) value was less than -45.3 dB with the thickness of less than 3 mm when the composite nanofibers absorber content was 10 wt%. Also, the maximum effective absorption bandwidth (EAB) exceeded 5 GHz. This study developed a neoteric structure to construct composite fibers loaded with nanowhiskers, and the TiO2@SiC/C nanofibers could be a remarkable candidate for broadband and efficient microwave absorbers. Also, the tunable wave-absorbing performance indicates a wide range of applications is possible under various environmental conditions.