Fabrication of flower-like surface Ni@Co3O4 nanowires anchored on RGO nanosheets for high-performance microwave absorption

Abstract

Novel composite microwave absorption (MA) materials with multiple loss mechanism have attracted considerable attention. In this work, flower-like surface Ni@Co3O4 nanowires were designed and fabricated through chemical reduction method induced by magnetic field, followed by in-situ polymerization, low temperature oil bath and thermal annealing. Then, the Ni@Co3O4/RGO composites were prepared through a hydrothermal reaction of the Ni@Co3O4 nanowires and graphene oxide suspension. The electromagnetic properties of different loading content samples (15 wt%, 25 wt% and 35 wt%) were measured to investigate the influence of loading content on the MA performance. For the 35 wt% loading sample, the minimum reflection loss (RLmin) value of −60.0 dB was determined at the thickness of 2.3 mm, and the maximum effective absorption bandwidth (EAB, RL < −10 dB) of 4.62 GHz can be achieved when the thickness is 1.6 mm. This research provides a reference for exploiting high-efficient flower-like surface magnetic-dielectric composites in the field of MA.