Ultrabroad band microwave absorption from hierarchical MoO₃/TiO₂/Mo₂TiC₂T_x hybrids via annealing treatment

Two-dimensional (2D) transition metal carbide MXene-based materials hold great potentials applied for new electromagnetic wave (EMW) absorbers. However, the application of MXenes in the field of electromagnetic wave absorption (EMA) is limited by the disadvantages of poor impedance matching, single loss mechanism, and easy oxidation. In this work, MoO₃/TiO₂/Mo₂TiC₂T_x hybrids were prepared by the annealing-treated Mo₂TiC₂T_x MXene and uniform MoO₃ and TiO₂ oxides in-situ grew on Mo₂TiC₂T_x layers. At the annealing temperature of 300 ℃, the minimum reflection loss (RL_min) value of MoO₃/TiO₂/Mo₂TiC₂T_x reaches −30.76 dB (2.3 mm) at 10.18 GHz with a significantly broadening effective absorption bandwidth (EAB) of 8.6 GHz (1.8 mm). The in-situ generated oxides creating numerous defects and heterogeneous interfaces enhance dipolar and interfacial polarizations and optimize the impedance matching of Mo₂TiC₂T_x. Considering the excellent overall performance, the MoO₃/TiO₂/Mo₂TiC₂T_x hybrids can be a promising candidate for EMA.