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In this paper, the MOFs-derived carbonaceous ZnO and RGO (carbonaceous ZnO/RGO) composites have been prepared by the wet chemical method and carbonization process. The as-prepared products are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), Raman spectra, thermogravimetric (TG) analysis and X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of carbonaceous ZnO/RGO composites are investigated by the vector network analyzer. The results exhibit carbonaceous ZnO/RGO composites have a maximum absorption of − 3 7. 1 2 dB at 6 GHz with thickness of 3.5 mm and the effective absorption (below − 1 0 dB) bandwidth is up to 1.92 GHz (from 5.28 to 7.2 GHz). Thus, the carbonaceous ZnO/RGO composites have great potential in the field of electromagnetic wave absorption. A simple wet chemical method has been employed to synthesize MOF and GO composites, and the MOF-derived carbonaceous ZnO and RGO are prepared by simple heat treatments of MOFs precursors and GO under inert gas condition. The carbonaceous ZnO/RGO composites also exhibit enhanced microwave absorption properties. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) derived carbonaceous metal oxides and their composite have unique structures and superior properties, thus they have been widely used in various fields. In this study, we use Co based MOFs (ZIF-67) and GO as precursors, synthesize carbonaceous Co 3 O 4 /Co/RGO composite as high performance EM wave absorbing materials. The derived carbonaceous Co 3 O 4 /Co microframes retain the ZIF-67 nanoparticles’ structure are well dispersed onto the surface of RGO nanosheets. Due to their porous structures and the well controlling of electromagnetic parameters, the obtained composite exhibits a maximum absorption of −52.8 dB at 13.12 GHz, and the bandwidth corresponding to −10 dB (90% absorption) is up to 10.72 GHz (from frequency of 4.88–15.6 GHz) with a coating layer thickness range of 2.0–4.0 mm. Therefore, the synthesized MOF-derived carbonaceous Co 3 O 4 /Co/RGO composite is a new promising candidate as highly useful microwave absorbers. [ABSTRACT FROM AUTHOR]

Associated with the unique structure and superior properties of zeolitic imidazolate frameworks (ZIFs) of Co-based metal-organic frameworks (MOFs), we synthesized the MWCNTs@carbonaceous CoO composites of a 3D interconnected network using multi-walled carbon nanotubes (MWCNTs) as decoration through the wet chemical and pyrolysis method. Due to the mutual coordination between proper magnetic loss and strong dielectric loss together with perfect impedance match, the MWCNTs@carbonaceous CoO composites exhibit the maximal reflection loss (RL) value of −50.2 dB with 1.84 mm thickness at 14.3 GHz, absorbing bandwidth (RL ≤ −10 dB) of 13.2 GHz (4.8–18 GHz) with respect to 1.0–4.0 mm thickness range. More importantly, the content of composites added to paraffin matrix is merely 10 wt%. In addition, the synergistic effect between CoO NPs and MWCNTs is also beneficial to the highly efficient electromagnetic (EM) wave absorption of the composites. Therefore, the obtained CoO NPs/MOF-derived composites with lightweight and thin performance can be an attractive candidate of the EM wave absorptive materials. Unlabelled Image • MWCNTs@carbonaceous CoO composite is prepared via wet chemical and pyrolysis method. • The composite can reach −50.2 dB at 14.3 GHz with the thickness of 1.84 mm. • The composite exhibits a bandwidth of 13.2 GHz at RL ≤ −10 dB in the range of 1.0–4.0 mm. • The composite shows a good performance of impedance match. [ABSTRACT FROM AUTHOR]