Morphology-controlled synthesis, characterization and microwave absorption properties of nanostructured 3D CeO2

Nanostructured 3D CeO2 have been synthesized by using PEG 2000 assisted simple hydrothermal technique. The impact of this novel approach on the structure, morphology, spectroscopy, complex permittivity and permeability was discussed. CeO2 was studied by employing X-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TG) and vector network analyzer. It can be seen that the microspheres of 1–3 μm in diameter were prepared at 600 °C with a mole ratio of 2:1, while the decreasing concentration of PEG-2000 resulted in the appearance of dim side-shape geometry. Obviously, the morphology of the synthesized CeO2 gradually changed from sphere with relatively smooth to irregular side-shape annealed at 600 °C with the increase of mole ratio for reactants. The electromagnetic (EM) wave absorption properties of the synthesized CeO2 were investigated over the range from 2 to 16 GHz, and minimum reflection loss (RL) with −19.3 dB was observed at 15.8 GHz with the thickness of 2.0 mm. This phenomenon may be attributed to both intrinsic characteristic of CeO2 and preparation with the function of PEG-2000.