Interface-engineered decoupled conductivity and relaxation: Synergistic modulation of Debye-parameters in N-doped SiO ₂ /MXene broadband wave-absorbing materials

The development of Ti₃C₂T_x MXene-based electromagnetic wave-absorbing materials faces a persistent challenge in balancing conductivity loss and polarization relaxation. To resolve this conflict, we propose an "interface engineering - Human-Computer Interaction (HCI)" strategy to regulate the evolution of permittivity and decouple the interdependency between conductivity (<em>σ</em>) and relaxation time (<em>τ</em>). First, by integrating the Debye relaxation model and transmission line theory into Python-based interactive modules, an HCI framework is established that quantitatively guides the optimization of permittivity trends and provides feedback on intrinsic Debye-parameter variations. Subsequently, guided by these theoretical optimizations, nitrogen-doped SiO₂-coated Ti₃C₂Cl_x MXene composites (SMX) are prepared via interface engineering. The insulating SiO₂ layer suppresses excessive <em>σ</em> while introducing heterogeneous interfaces that prolong <em>τ</em>. Meanwhile, the surface heterogeneous dipole generated by nitrogen-doping induces a hysteresis of <em>τ</em>. Consequently, this theory-guided design enables the optimized SMX-S2-N1 to achieve a 5.2 GHz effective absorption bandwidth, overcoming the inherent limitation of narrow absorption bandwidth in MXene single-component materials. This study not only addresses the restricted absorption bandwidth of monolithic MXenes but also offers a mechanistic understanding of dielectric loss through Debye model analysis, bridging semi-empirical design principles with theoretical frameworks.&nbsp;