Facile synthesis of rod-like nickel cobaltite decorated reduced graphene oxide composites with excellent microwave absorption performance

Abstract

Herein, rod-like nickel cobaltite decorated reduced graphene oxide (NiCo2O4/RGO) composite materials were synthesized by a facile hydrothermal method combined with heat-treatment process. Noticeably, this route produced a composite structure with multiple interfaces and large aspect ratio, in which two-dimensional RGO nanosheet uniformly wrapped rod-like NiCo2O4. Furthermore, the microwave absorption performance of the as-synthesized NiCo2O4/RGO composites could be adjusted well by changing the mass ratio of the precursor (NiCo-pre: GO). Particularly, when the mass ratio of NiCo-pre to GO was 3, the minimum reflection loss (RLmin) at 5.92 GHz and a thickness of 3.47 mm was −64.50 dB, meanwhile, its effective absorption bandwidth (RL < −10 dB) reached 5.28 GHz (from 12.72 to 18.00 GHz) at a thin thickness of 1.56 mm. Based on these results, the NiCo2O4/RGO composites are expected to be promising candidates for high-performance microwave absorbers.