Tailoring the carbon nanofibers with Ti3C2Tx MXene as precursor to enhance the electromagnetic attenuation properties

Carbon nanofibers can be widely used in the field of electromagnetic wave absorption due to corrosion resistance, low density and good chemical stability. Here, we report a strategy to achieve strong microwave absorption capability by adjusting the crystallinity of carbon nanofibers containing Al₂O₃ and TiO₂. TiO₂ with Ti₃C₂T_x MXene as a precursor decreases the crystallization temperature of Al₂O₃ from 1400 °C to 800 °C in the carbon nanofibers. The diameter distribution of carbon nanofibers is uniform, though the surface of carbon nanofibers is getting rough with Ti₃C₂T_x content increasing. The minimum reflection loss of carbon nanofibers is −55.78 dB at a thickness of 4.32 mm; the effective absorption bandwidth reaches 5.41 GHz (12.59–18 GHz) at a thickness of 1.67 mm, almost covering the Ku band. The excellent microwave absorption performance can be attributed to the synergistic effect of the non-crystalline carbon matrix and crystalline Al₂O₃/TiO₂, in which the former improves impedance matching with free space, while the latter enhances the attenuation capability to the electromagnetic wave.