Preparation of MWCNT/Fe3O4/Si3N4 ternary composite material and microwave absorption properties

MWCNT/Fe3O4/Si3N4 composite was synthesized via hydrothermal synthesis. The morphology and structure of MWCNT/Fe3O4/Si3N4 were investigated by means of SEM, XPS, XRD, and FT-IR. Their electromagnetic parameters were measured by a vector network analyzer. The microwave attenuation properties of as-synthesized composite could be modulated by regulating the feed ratio of MWCNT, Fe3O4, and Si3N4. According to the different amounts of modified nano Fe3O4 added, they are labelled as S1-S3. When the feed ratio is 3:15:20, the maximum reflection loss value of the sample is −23.3 dB at 14.4 GHz, the corresponding thickness is 2.5 mm, and the corresponding effective absorption bandwidth is 5.36 GHz. Moreover, the test results of the thermogravimetric analyzer show that the composite material has excellent heat resistance. Our research results provide a reference value for the development of excellent heat resistance and high-performance MWCNT-based microwave absorption composite materials.