Stable microwave absorber derived from 1D customized heterogeneous structures of Fe3N@C

Synthetic customized heterostructure via optimizing structure as well as designing components is considered as an effective strategy to endow materials with specific functional applications. Here, we reported a facile and green process to obtain one dimensional (1D) Fe3N@C heterogeneous structures by using organic amines as nitrogen and carbon sources. Multiple processes including nitridation, formation of Fe3N nanoparticles and encapsulation of the produced Fe3N nanoparticles are simultaneously achieved. It is well known that microwave absorbers with stability and excellent performance are very important for the practical application. In this work, the as-prepared Fe3N@C composites can maintain excellent microwave absorbing performance when the samples are exposed to the open air for 3 months. Wide effective absorption bandwidths and strong absorption can be gained with the thickness less than 2 mm. In particular, an effective absorption bandwidth as wide as 5.92 GHz was obtained with thickness of 1.8 mm. Furthermore, the vector network analyzer (VNA) tests after 9 months of exposure to air provide more favorable evidence for its excellent and stable absorbing properties. The strong stability should be attributed to the covalent bonds after nitriding and the air-barrier provided by the outer carbon base. This study may provide new insights into the design and development of high-performance electromagnetic wave absorbers with excellent stability.