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

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.

Automated summary

The study focused on designing single and double layer microwave absorbers using FeCoNi@C metal organic framework and MWCNTs. It was found that the double-layer absorber showed wider absorption bandwidth and lower reflection loss compared to the single-layer absorber, while the single-layer absorber also exhibited good absorption performance at certain frequencies.