Toward enhancing the electromagnetic wave absorption performance of CeFe-PBA derived composites: morphology control

The preparation of high-efficiency electromagnetic wave (EMW) absorption materials usually requires the matching of dielectric and magnetic components. However, simultaneously tuning the dielectric and magnetic properties of materials still faces a significant challenge. Herein, a series of metal/carbon-based CeO₂/Fe₃C/CNT (CF-CNT-x, x = 1, 2, 3) composites derived from Ce-based Prussian blue analogues (Ce[Fe(CN)₆]·5H₂O, CeFe-PBA) with different morphologies via adjusting the solvent environment was prepared. The composites not only inherit the morphology of the CeFe-PBA precursors but also generate a large number of carbon nanotubes (CNTs), further tuning the balance of dielectric and magnetic components. Due to the highest anisotropy bipyramidal morphology, multi-polarization mechanisms, and magnetic-dielectric synergies, the obtained CF-CNT-2 exhibits excellent EMW absorption performance with a filling ratio of merely 20 wt%, a minimum reflection loss (RL_min) of -62.60 dB and an effective absorption bandwidth (EAB) of 5.28 GHz at 2.00 mm. Meanwhile, CST simulations show that the maximum radar cross-section reduction of CF-CNT-2 reaches 31.63 dB m², confirming its great practical application potential. This work effectively elucidates the mechanism of the influence of the morphology of PBA-based EMW absorption materials on the dielectric and magnetic properties, and confirms the great potential of rare earth (RE)-based PBA derivatives as EMW absorption materials.