Electromagnetic wave absorption characteristics of single and double layer absorbers based on trimetallic FeCoNi@C metal−organic framework incorporated with MWCNTs

Abstract The present study focuses on the design of single and double layer microwave absorbers based on FeCoNi@C metal−organic framework incorporated with MWCNTs. FeCoNi@C metal−organic framework (MOF) and MWCNTs decorated with MOF (MW/MOF) were successfully synthesized via hydrothermal method and characterized with XRD, VSM and FESEM. The electromagnetic parameters of material (complex permittivity and permeability) of the as-prepared nanocomposites dispersing in paraffin (30 wt% powder, single layer) were evaluated by a vector network analyzer in X-band frequency range. The simulation of microwave absorption performance of single- and double-layer absorbers was performed via CST Studio software. The results indicate that the double layer absorber using M/MOF structure as matching layer and MOF structure as absorbing layer can increase the microwave absorption bandwidth up to 4 GHz and greatly decrease the reflection loss down to −36 dB for a total thickness of 2 mm. In contrast, the single layer microwave absorber consisting of 30 wt% M/MOF composite structure exhibited a minimum reflection loss of −18 dB at 9 GHz with 2 GHz bandwidth and 2.5 mm thickness. The better absorption performance of the double-layer absorber maybe attributed to the better impedance matching ability of M/MOF layer, coupling interactions between two distinctive layers (absorbing and matching layers) and excellent magnetic loss ability of MOF layer.