CNT-coupled 2D-MOF composite materials enable tunable bandwidth electromagnetic wave absorption

The rational design of heterogeneous interfaces is considered an effective strategy for developing advanced electromagnetic wave (EMW) absorbers. Herein, a novel inter-dimensional 1D/2D heterostructure was prepared by arranging a typical semiconductive metal-organic framework, CuHT (HT, 4-hydroxybenzenethiol), on conductive networks constructed from different kinds of carbon nanotubes (CNTs) through a one-step in situ polymerization method. The unique heterostructure endowed the designed composite with remarkable EMW absorption performance. In contrast to pristine CuHT nanosheets and carbon nanotubes, the as-prepared CNT/CuHT composite not only displayed excellent reflection loss (RL) performance, but also achieved a broad absorbing bandwidth. The widest bandwidth could be gained up to 6.36 GHz, and the optimal RL was −59.24 dB at 14.04 GHz. Further through precise combination with different types of CNTs, the effective absorption to specific microwave frequency bands can be well optimized. The EMW absorption performance results showed that the MCNT-CuHT and HCNT-CuHT samples could achieve almost full absorption in Ku-band and X-band, respectively. This newly 1D/2D coupled CNT/CuHT concept provided a controllable preparation process, enhanced performance, and an intelligent strategy for electromagnetic wave absorber design and practical applications.