TiO2 Nanosheets/Ti3C2Tx MXene 2D/2D Composites for Excellent Microwave Absorption

Ti 3 C 2 T x MXene is a potential microwave absorption material due to its unique physical and chemical properties. However, the impedance mismatch of MXene results in low microwave absorption. In this work, 2D/2D MXene@TiO 2 composites were synthesized via a simple hydrothermal oxidation method, TiO 2 is derived in situ from MXene without adding any additional Ti precursors. TiO 2 with low permittivity can effectively regulate the impedance matching and enhance loss mechanisms. The MXene@TiO 2 -6 h composite shows a reflection loss (RL) of −58.3 dB at 11.36 GHz with a thickness of 1.75 mm, and the maximum effective absorption bandwidth (EAB) is 4.08 GHz (13.92–18 GHz) at 1.26 mm. Furthermore, the 2D/2D composite can obtain efficient microwave absorption at different frequencies by adjusting the thickness; RL can reach −39.1 dB at 5.04 GHz with a thickness of 3.5 mm. The radar cross section (RCS) of MXene@TiO 2 -6 h is lower than −19 dB m 2 at −60–60°, and the minimum RCS is −56 dB m 2 at 15°. This work provides a valuable experience in developing microwave absorption materials.