TiO2 Nanosheets/Ti3C2T x MXene 2D/2D Composites for Excellent Microwave Absorption

Ti3C2T x MXeneis a potential microwave absorption material due to its unique physicaland chemical properties. However, the impedance mismatch of MXeneresults in low microwave absorption. In this work, 2D/2D MXene@TiO2 composites were synthesized via a simple hydrothermal oxidationmethod, TiO2 is derived in situ from MXene without addingany additional Ti precursors. TiO2 with low permittivitycan effectively regulate the impedance matching and enhance loss mechanisms.The MXene@TiO2-6 h composite shows a reflection loss (RL)of -58.3 dB at 11.36 GHz with a thickness of 1.75 mm, and themaximum effective absorption bandwidth (EAB) is 4.08 GHz (13.92-18GHz) at 1.26 mm. Furthermore, the 2D/2D composite can obtain efficientmicrowave 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@TiO2-6 h is lowerthan -19 dB m(2) at -60-60 & DEG;, andthe minimum RCS is -56 dB m(2) at 15 & DEG;. This workprovides a valuable experience in developing microwave absorptionmaterials.