Enhanced electromagnetic wave absorption performances of Co3O4 nanocube/reduced graphene oxide composite

•Co3O4 nanocube/RGO composite paper has been firstly synthesized by a simple process.•The average edge length of the Co3O4 nanocubes onto RGO is about 200nm.•The maximum RL of Co3O4/RGO composite is −32.3dB at 12.4GHz with a thickness of 2.5mm.•The absorption bandwidth of Co3O4/RGO composite with the RL below −10dB is 10.5GHz. The Co3O4 nanocube/reduced graphene oxide (Co3O4/RGO) composite paper has been firstly fabricated via a simple process. Several analytical techniques including X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been employed to characterize the Co3O4/RGO composite. The results indicated that the Co3O4 nanocubes attached to the RGO sheets, and that the average edge length of Co3O4 nanocubes is about 200nm. The obtained composite exhibited a maximum reflection loss of −32.3dB at 12.4GHz with a coating layer thickness of 2.5mm, and the effective absorption bandwidth with reflection loss less than −10dB is up to 10.5GHz (from 5.5 to 16.0GHz) when an appropriate absorber thickness between 2 and 5mm is chosen. Such high microwave absorption composite can be used as promising candidate for the new type of electromagnetic wave absorptive material.