Multiple-loss-enhanced NiOx@carbon spheres/reduced graphene oxide-based composite for tuneable elimination of electromagnetic signals

Abstract

In this work, a novel graphene-based ternary composite NiOx@CS/reduced graphene oxide (rGO) consisting of magnetic nanoparticles (NiOx) and porous carbon spheres (CS) were successfully synthesised through facile hydrothermal and high-temperature sintering approaches. Owing to the ternary structure, the dielectric and magnetic capacity of the composite was improved. Further, the synergistic effect of two loss mechanisms improves the absorption efficiency of electromagnetic waves. The maximum reflection loss of NiOx@CS/rGO-20 wt% was −69.3 dB at 7.2 GHz and the absorption bandwidth with reflection loss below −10 dB was 4.04 GHz (6.36–10.4 GHz). Hence, the NiOx@CS/rGO ternary composite with a combination of dielectric and magnetic loss-facilitated absorption provides a new design paradigm for tuneable elimination of electromagnetic signals.