Non‐Equilibrium Pyrolysis Enables Nano‐Confined Hetero‐Interfaces in MOF‐Derivatives for Advanced Dielectric Engineering

Interfacial polarization is a cornerstone of dielectric engineering, yet the thermal processing required for interface construction typically triggers grain coarsening, thereby undermining interfacial density and dielectric performance. Here, a microwave non‐equilibrium pyrolysis strategy is developed to overcome this bottleneck. By preprogramming compositional heterogeneity in a Zn‐Ni bimetallic MOF and introducing a carbon nanotube (CNT) scaffold with strong microwave coupling capability, rapid structural reconstruction is achieved on a second‐level timescale. Microwave‐induced plasma arc discharge and transient thermal shock facilitate the confined nucleation and nanoscale dispersion of ZnO/NiO within N‐doped carbon, creating a dense multiphase heterogeneous interface. This non‐equilibrium pathway effectively suppresses structural relaxation, significantly boosting interfacial polarization and localized electric‐field perturbations. Consequently, the MOF‐derivatives achieve potent electromagnetic wave attenuation reaching a minimum reflection loss of −55.16 dB at 1.85 mm. Furthermore, this second‐level strategy enables the energy‐efficient and high‐throughput production of heterogeneous powders, which, when integrated into macro‐periodic architectures, achieve an ultra‐wide bandwidth of 11.98 GHz. This work establishes a non‐equilibrium pyrolysis paradigm that enables next‐generation electromagnetic wave absorbers with integrated ultra‐wideband performance and a minimal energy footprint.