Fabrication of reduced graphene oxide (RGO)/Co₃O₄ nanohybrid particles and a RGO/Co₃O₄/poly(vinylidene fluoride) composite with enhanced wave-absorption properties

Reduced graphene oxide (RGO)/Co₃O₄ nanohybrid particles, composed of reduced graphite oxide and Co₃O₄ particles, have been fabricated by an in situ growth method under mild wet-chemical conditions (140°C). A series of characterization results indicate that the as-prepared Co₃O₄ particles with relatively uniform sizes are embedded in RGO layers to form unique core-shell nanostructures. The RGO/Co₃O₄/poly(vinylidene fluoride) composite was found to possess excellent absorption properties. Owing to the effect of the negative permeability, the position of the absorption peaks remains at the same frequency at different thicknesses without shifting to lower frequencies. For the composites with a filler loading of 10 wt %, the maximum peaks can reach -25.05 dB at 11.6 GHz with a thickness of 4.0 mm. These enhanced microwave absorbing properties can be explained based on the structures of the nanohybrid particles.