Phase engineering and interfacial polarization synergistic modulation: high-efficiency electromagnetic wave absorption performance of Ti3C2Tx-based dielectric composites

Driven by the rapid deployment of 5G/6G infrastructures and next-generation radar technologies, there is an escalating requirement for ultrathin, lightweight electromagnetic wave absorbers capable of delivering robust attenuation across high-frequency regimes (12–18 GHz). Ti₃C₂Tₓ MXene emerges as a promising candidate but is plagued by significant impedance discrepancies arising from its extraordinarily large permittivity. Herein, a dual-regulation strategy integrating crystal phase engineering and heterointerface design is proposed. Systematic investigations on Ti₃C₂Tₓ-MXene and derived ZnO/TiO₂ ternary composites reveal that 20 wt% filler loading yields optimal impedance matching, achieving a minimum reflection loss (RL min ) of –20.72 dB at 8.32 GHz. To further enhance performance, a ternary system was constructed via gradient-temperature treatment (300, 700, and 800 °C), enabling controlled TiO₂ phase evolution. The ZTM-2 sample (700 °C) exhibits exceptional performance at 1.4 mm thickness, with RL min of –47.54 dB and an effective bandwidth of 2.72 GHz. This is ascribed to the synergy of strong interfacial polarization, dipole relaxation from ZnO defects, and modulated dielectric properties. Rational regulation of filler concentration and microstructure effectively balances impedance matching and loss capability, offering new strategies for high-performance MXene-based absorbers.