Mixed-phase TiO₂ as an intrinsic polarization engine to amplify multi-level interfacial synergy for high-performance electromagnetic wave absorption

Electromagnetic pollution has become a serious issue, but conventional absorbers often suffer from a trade-off between absorption strength and bandwidth, while traditional interfacial engineering ignores intrinsic polarization within materials. To address this challenge, we propose a strategy to tune electronic structures by integrating anatase/rutile (A/R) mixed-phase TiO₂ into a MoSe₂/nitrogen-doped carbon (NC) matrix. The A/R-TiO₂ acts as an intrinsic polarization engine, inducing spontaneous charge separation and constructing built-in electric fields at phase boundaries, thereby enhancing polarization loss capability. Abundant phase boundaries and structural defects in mixed-phase TiO₂ also serve as charge traps, extending charge relaxation pathways and synergistically enhancing both polarization loss and conductive loss. Combined with density functional theory calculations, electron paramagnetic resonance, and systematic characterizations, this intrinsic polarization amplifies heterogeneous interfacial polarization, defect polarization and dipole polarization, forming an efficient multi-polarization coupling system. The optimized composite achieves a minimum reflection loss of −54.04 dB at 2.18 mm and a broad effective absorption bandwidth of 5.84 GHz. Radar cross-section simulations further confirm its potential for practical radar stealth. This work clarifies the polarization amplification mechanism of TiO₂ phase junctions and provides a new route for designing high-performance electromagnetic wave absorbers.