Graphite-ring-stacked carbon nanotubes synthesized during the rescue of Ti3C2Tx MXene for dual-peak electromagnetic wave absorption

As a new member of the two-dimensional material family, Ti ₃C ₂T _x MXenes have gained considerable attention for electromagnetic wave absorption applications. Herein, a graphite-ring-stacked carbon nanotube (CNT)/Ti ₃C ₂T _x MXene composite with a three-dimensional network structure was fabricated via a vacuum freeze-drying process followed by a vacuum in situ growth at ultra-low temperatures. The well-designed process effectively protects the MXene structure from being damaged by high temperatures and prevents its oxidation. To the best of our knowledge, this study is the first to report on graphite-ring-stacked CNTs. The obtained CNT/MXene composite exhibited a minimal reflection loss of − 47.28 dB and an effective absorption bandwidth of 4.16 GHz at low sample thicknesses of 1.36 and 1.16 mm, respectively. Moreover, owing to its strong polarization and interference-type loss, the CNT/MXene composite exhibited unique impedance matching and reflection loss curves with dual-peak characteristics, which effectively broadened its absorption bandwidth. This work provides insights into MXene-based electromagnetic wave absorbers with enhanced absorption properties through microstructure design and multi-component synthesis strategies.