Solvothermal synthesis, electromagnetic and electrochemical properties of jellylike cylinder graphene-Mn3O4 composite with highly coupled effect

Jellylike cylinder graphene-Mn3O4 composite with highly coupled effect was successfully synthesized by a simple solvothermal process. Without using toxic reducing agent and expensive equipment, this method is environmental compatible and suitable for low cost mass production. High capacitance Mn3O4 nanoparticles are homogeneously anchored on excellent conductivity graphene framework and a growth mechanism is hypothesized. Excellent electron conductivity and unique structure of Mn3O4-graphene composite give rise to various applications such as microwave absorber and electrode material. As a microwave absorber, the composite exhibits lowest reflection loss of -14.2 dB in the frequency range of 2-18 GHz. Good microwave absorption performance is due to the structure of the composite where conductive channels form between nano sized Mn3O4 and high conductivity graphene with defects and dangling bonds. As for electrochemical property, Mn3O4-graphene composite with coupled effect shows excellent performance with highest specific capacitance of 246.7 F g(-1) in saturated K2SO4 at a scan rate of 5 mV s(-1). Good electrochemical property is also attributed to the structure with high utilization of Mn3O4, fast charge carrier transmission, and excellent electronic conductivity. This composite shows a promising application in absorbing materials and electrodes.