Enhanced\nElectromagnetic Microwave Absorption Property of Peapod-like MnO@carbon\nNanowires

Abstract

Investigating\nlightweight electromagnetic microwave absorption materials is still\nurgent because of the issue related to the electromagnetic pollution\nor military defense. Our findings indicate that core–shell\nMnO@carbon nanowires (MnO@C NWs) achieve substantially enhanced microwave\nabsorption, suggesting the suitable impedance matching induced by\nthe synergetic effect between MnO and carbon. Furthermore, the peapod-like\nMnO@C NWs with internal void space can be facially synthesized by\npartial etching of core–shell MnO@C NWs. The peapod-like MnO@C\nNWs with internal voids/cavities exhibit dramatically enhanced electromagnetic\nmicrowave absorption property when the carbon content is about 64\nwt %, a minimum reflection loss (RL) of −55 dB at 10 wt % loading\nwas observed at 13.6 GHz, and the bandwidth of RL less than −10\ndB (90% absorption) covers 6.2 GHz at the thickness of 2 mm. The excellent\nelectromagnetic microwave absorption performance is superior to the\nmost of MnO<i>_x</i>/C composites in the literatures,\nwhich probably benefits from the dielectric polarization among conductive\nnetwork structure between MnO and carbon, as well as the multiple\nreflection and absorption induced by internal void space. Our work\nis expected to pave an effective way to extend the electromagnetic\nmicrowave absorption performance of MnO/C composites through partial\netching to create a void space.