Construction of caterpillar-like hierarchically structured Co/MnO/CNTs derived from MnO2/ZIF-8@ZIF-67 for electromagnetic wave absorption

Metal-organic frameworks (MOFs) derived carbon-based composites exhibit great potential in the fields of electromagnetic wave (EMW) absorption. However, which kind of MOFs derivative structure has better electromagnetic wave absorption is an urgent problem to be addressed. Herein, caterpillar-like hierarchically structured Co/MnO/CNTs was successfully prepared by pyrolysis of core-shell manganese dioxide and zeolitic imidazolate framework template. The material shows excellent EMW absorption performance in different frequencies range based on the hierarchical structure. Owing to the unique distribution of carbon nanotubes on the caterpillar-like hierarchical structure, the generated multi heterogeneous interfaces and local conductive network are beneficial to interfacial polarization, conduction loss, matched impedance as well as multiple scattering. The composite composites present outstanding EMW absorption achieved with effective absorption bandwidth covering from 13.52 GHz to 18 GHz with thickness of only 1.32 mm. Moreover, the composite also demonstrates a microwave absorption with the qualified frequency bandwidth of 5.36 GHz, and a strong reflection loss of −58.0 dB with a low filling amount of 35%. The result provides a new approach for developing EMW absorbing materials with hierarchical structure.