Structure design of Prussian blue analogue derived CoFe@C composite with tunable microwave absorption performance

Manufacturing microwave absorbers with controllable microstructure is appealing continuous interest. Here, tunable structure of cobalt hexacyanoferrate submicrocubes (CoHCF) are fabricated via cation exchange method. Subsequently, porous cobalt iron alloys and carbon (CoFe@C) composites are obtained through annealed the CoHCF precursors at 500 degrees C. By simply adjust the reaction solvent of precursors, the CoHCF submicrocubes with yolk-shell, hollow, and mesoporous structure are obtained. The results show that the morphology and structure are important for enhancing the microwave absorption properties. Typically, the optimal reflection loss of CoFe@C submicrocubes with mesoporous structure is -73.63 dB at the absorber thickness of 2.6 mm, and the effective absorption bandwidth (EAB, RL < -10 dB) is 5.0 GHz. This strategy provides a novel approach for the structural control of Prussian blue analogous (PBAs), which may be greatly helpful for the wide application of PBAs and their derivatives.