Self-template and in-situ synthesis strategy to construct MnO2/Mn3O4@Ni-Co/GC nanocubes for efficient microwave absorption properties

The combination of magnetic nanoparticles and transition metal oxides has attracted much attention in microwave absorption applications. Herein, the MnO2/Mn3O4@Ni-Co/graphite carbon (GC) nanocubes with porous structure and ultrathin nanosheets was constructed by self-template strategy and in-situ synthesis. The composites not only synergize the magnetic loss of magnetic Ni-Co nanoparticles with the dielectric losses of GC and MnO2/Mn3O4 , but also enhance the multiple interface polarization and improve impedance matching. As a result, the MnO2/Mn3O4 @Ni-Co/GC nanocubes present outstanding electromagnetic wave (EMW) absorption performances, in which a RLmin of -26 dB at 6.4 GHz with a thickness of 4 mm and an effective absorption bandwidth covering from 5.3 GHz to 6.4 GHz are achieved. Meanwhile, the widest effective absorption bandwidth with the value of 3.7 GHz can be achieved at a matching thickness of 2.0 mm. More importantly, this work provides a new strategy for the synthesis of EMW absorbing materials. (C) 2021 Published by Elsevier B.V.