Construct of flake-like NiCo2O4/reduced graphene oxide/melamine-derived carbon foam as an excellent microwave absorber

Carbon-based foams with a three-dimensional (3D) structure can provide a lightweight template for the rational design and controllable preparation of metal oxide/carbon-based composite microwave absorption materials. In this study, the flake nickel cobaltate/reduced graphene oxide/melamine-derived carbon foam (FNC/RGO/MDCF) was successfully fabricated by solvothermal treatment combined with high temperature pyrolysis. The results indicated that RGO was evenly interspersed in the MDCF skeleton, providing an effective support for the load growth of FNC on its surface. The sample S3 had a minimum reflection loss (RLmin) of -66.44 dB at a thickness of 2.29 mm. When the thickness was 1.50 mm, the optimal effective absorption bandwidth (EAB) was 3.84 GHz. The analysis of the absorption mechanism of FNC/RGO/MDCF showed that the excellent absorption performance of FNC/RGO/MDCF was mainly dependent on the combined action of conduction loss, multiple reflection, scattering, interface polarization and dipole polarization.