Synthesis of porous carbon nanoparticles anchored on MnO nanosheets for enhanced microwave absorption

Dielectric loss materials play a vital role in microwave absorption field due to their excellent permittivity, good chemical stability and lightweight feature. In this work, a high-efficiency dielectric absorber of MnO nanosheets supported nanoporous carbon particles (MnO/NPC) was successfully fabricated by a pyrolysis of MnO2/ZIF-8 precursor. The ZIF-8 derived NPC with an even diameter of ca. 80 nm are firmly attached on both sides of MnO nanosheets. This unique nanostructure could effectively enhance the attenuation ability and optimize the impedance matching. When the pyrolysis temperature is 850 °C, the obtained MnO/NPC exhibit a strong reflection loss (RL) of -52.2 dB and broad effective absorption bandwidth (EAB) of 5.8 GHz at a thin thickness of 1.85 mm. The remarkable microwave absorption performance is apparently superior to the single manganese oxide and NPC. Our work is expected to pave an effective way to improve the microwave absorption performance of dielectric loss type composites.