Low-temperature synthesis and microwave absorbing properties of Mn3O4-graphene nanocomposite

A low-temperature synthesis method for Mn3O4/graphene is described in this research. Adjusting the reaction time and temperature allows control over the phase and morphology of the synthesized manganese oxide, and therefore the microwave absorbing properties. X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and vector network analysis are used to characterize the phase, morphology, and electromagnetic properties. The results reveal that long reaction time can increase the particle size and high temperature can destroy the initial structure of graphene both of which have negative impact on the microwave absorbing properties. The Mn3O4-graphene composite synthesized in 140 degrees C for 4 h shows a maximum reflection loss (RL) reaching -20 dB at 14.4 GHz with absorber thickness of 2 mm, as well as an effective absorption bandwidth of more than 5 dB corresponding to RL below -10 dB.