Preparation and microwave absorption of porous hollow ZnO by CO2 soft-template

Abstract

The porous hollow ZnO samples were prepared by calcination of ZnCO3 precursor at 450°C. The structural properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis and differential thermal analysis (TG-DTA). A possible mechanism for the formation of porous hollow microstructure was proposed. The microwave absorption properties of the porous hollow structural ZnO have been investigated. The reflection loss (RL) of the ZnO was calculated based on the relative complex permeability and permittivity. A minimum reflection loss of the wax-composite with 25wt% porous hollow ZnO is −36.3dB at 12.8GHz with a thickness of 4.0mm. The results indicate that porous hollow structural ZnO can be used as a desirable material for the microwave absorption.