Reduced graphene oxide decorated with in-situ growing ZnO nanocrystals: Facile synthesis and enhanced microwave absorption properties

Reduced graphene oxide (RGO) was decorated with well dispersed ZnO nanocrystals with narrow grain size distribution by a facile in-situ growth strategy. Zinc ions were absorbed on graphene oxide (GO) sheets through interaction with functional groups in absolute ethanol. After adding hydroxyl ions, the precursor of ZnO formed on GO sheets and crystallized after thermal treatment during which the GO was reduced. The RGO/ZnO nanocrystals composites were mixed with wax with different mass fraction (5, 10, 15, 20 wt%) to examine the dielectric and microwave absorption properties. The sample loaded with 15 wt% composites exhibits the most prominent microwave absorption properties, with strong absorption (maximum reflection loss of −54.2 dB), broad effective absorption bandwidth (6.7 GHz) and small thickness (2.4 mm). The microwave absorption mechanism of the composites mainly based on the conduction loss and dielectric loss was discussed. The RGO/ZnO nanocrystals composites in this study are very promising as strong absorption and light weight microwave absorber.