MOF-on-MOF Heterostructured Films for Broadband Electromagnetic Wave Absorption and Thermal Management

Understanding the correlation between heterointerface engineering and electromagnetic (EM) properties in hybrid materials, including metal–organic frameworks, is critical to advancing next-generation high-performance electromagnetic wave (EMW) absorbers. As the first demonstration of an all-MOF heterostructure film that achieves both high-performance EM absorption and thermal management, herein, a heterostructured MOF film, NUS-8@Cu₃(HHTP)₂, was fabricated by hybridizing the solution-processable MOF NUS-8 with the highly conductive MOF Cu₃(HHTP)₂. This prototypical heterostructure NUS-8@Cu₃(HHTP)₂ was found to exhibit effective modulation of its dielectric loss behavior. The optimal composite exhibits a notable minimum reflection loss (RL_min) of –42.9 dB and an ultra-wide effective absorption bandwidth (EAB) of 8.47 GHz at 2.5 mm, setting up new benchmarks over conductive MOFs and MOF composites reported thus far. When the optimized NUS-8@Cu₃(HHTP)₂ composite was incorporated into an epoxy matrix, a stable and robust EMW absorbing patch featuring an RL_min of –33.2 dB and an EAB of 6.38 GHz was achieved. Of particular importance is that NUS-8@Cu₃(HHTP)₂ epoxy composites demonstrate an enhanced thermal conductivity, eliciting efficient heat dissipation for reliable use in thermally demanding environments. Put simply, this work introduces a new strategy for designing high-performance EM absorbers through heterostructure engineering.