Synthesis and excellent electromagnetic absorption properties of polypyrrole-reduced graphene oxide-Co₃O₄ nanocomposites

A novel kind of polypyrrole-reduced graphene oxide-Co₃O ₄ (PPy-RGO-Co₃O₄) nanocomposites was firstly synthesized by a three-step method. The results indicate that small Co ₃O₄ nanoparticles with the sizes in the range of 10-30 nm are anchored on the surface of PPy-RGO. The results demonstrate that the maximum reflection loss of PPy-RGO-Co₃O₄ is -33.5 dB at 15.8 GHz with a thickness of 2.5 mm and the absorption bandwidth with the reflection loss below -10 dB is up to 11.4 GHz (from 6.6 to 18.0 GHz) with a thickness in the range of 2-4 mm, suggesting that the microwave absorption properties and the absorption bandwidth are obviously enhanced by adding Co₃O ₄ nanoparticles. Such strong microwave absorption materials could be used as a kind of candidate for the new types of microwave absorbing materials.