Porous structure to improve microwave absorption properties of lamellar ZnO

- The novel porous lamellar ZnO was prepared by a facile two-step method.
- The novel porous lamellar ZnO exhibits enhanced microwave absorption properties.
- The minimum reflection loss of porous lamellar ZnO is −34.5 dB at 10.7 GHz.
- The good properties were mainly attributed to multi-reflection of porous structure.

The novel porous ZnO nanoflakes were fabricated by a facile two-step method containing preparation of precursor ZnCO3 and subsequently calcination of ZnCO3. The as-prepared products were analyzed by X-ray diffraction, scanning electron microscopy, and thermalgravimetric analysis. The results reveal that the porous ZnO nanoflakes were in the diameter and thickness of several to tens micrometers and 100-500 nm, respectively. The microwave absorption properties of porous ZnO nanoflakes were investigated by the network analyzer, which exhibit the minimal reflection loss of −34.5 dB at 10.7 GHz with only thickness of 1.5 mm. The effective absorption (below −10 dB) bandwidth can be tuned between 7.0 GHz and 17.1 GHz by tuning absorber thickness of 1.0-2.2 mm. Thus, the porous lamellar ZnO could be used as a promising absorbing material with the features of high efficiency absorption, wide-band and light weight.

The porous lamellar ZnO nanostructures present the enhanced microwave absorption properties.115