3D porous coral-like Co1.29Ni1.71O4 microspheres embedded into reduced graphene oxide aerogels with lightweight and broadband microwave absorption

[Display omitted] In this work, three-dimensional (3D) porous coral-like Co1.29Ni1.71O4 microspheres were successfully combined with reduced graphene oxide (rGO) to form Co1.29Ni1.71O4/rGO aerogels as an efficient microwave absorber by a facile calcination and hydrothermal method. The elemental composition, microstructure, and morphology of the as-synthesized composites were characterized, and the electromagnetic wave absorption performance were analyzed in the frequency range of 2.0–18.0 GHz. The results show that adjusting the mass ratio of Co1.29Ni1.71O4 microspheres and rGO in the composites can effectively tune the electromagnetic parameters, which in turn improves their microwave absorption performance. Here, the minimum reflection loss (RLmin) of the Co1.29Ni1.71O4/rGO aerogels is −51.76 dB with an effective absorption bandwidth (RL