Fabrication of carbon encapsulated Co3O4 nanoparticles embedded in porous graphitic carbon nanosheets for microwave absorber

Carbon-encapsulated Co3O4 nanoparticles homogeneously embedded 2D (two-dimensional) porous graphitic carbon (PGC) nanosheets were prepared by a facile and scalable synthesis method. With assistance of sodium chloride, the Co3O4 nanoparticles (10–20 nm) with magnetic loss were well encapsulated by onion-like carbon shells homogeneously embedded porous graphitic carbon nanosheets (thickness of less than 50 nm) with dielectric loss. In the architecture, the well impedance matching for microwave absorption can be obtained by the synergetic effect between Co3O4 nanoparticles and encapsulated porous carbon nanosheets. The minimum reflection loss value of −32.3 dB was observed at 11.4 GHz with a matching thickness of 2.3 mm for 2D Co3O4@C@PGC nanosheets. The 2D Co3O4@C@PGC nanosheets can be used as a kind of candidate for microwave absorbing materials.