Sea Urchin-like SnS/Nitrogen-Doped Carbon Nanotube Dielectric Composites for Tunable Electromagnetic Response

Owing to the unique energy band structure, semiconductor property, and adjustable morphology of two-dimensional SnS nanomaterials, it is extremely practical to employ them as dielectric microwave absorbers. However, electrical conductivity restricts the dielectric characteristic of SnS, resulting in a higher filling rate in real-world applications. Herein, sea urchin-like SnS/N-doped carbon nanotube (N-CNT) heterogeneous frameworks are fabricated by using the self-assembly solvothermal method to further upgrade the performance of SnS-based microwave absorbers. The flower-like SnS nanosheets are chained by way of one-dimensional conductive N-CNTs to shape three-dimensional (3D) hierarchical composites. In particular, the frameworks with a cross-linking nanoarchitecture provide an effective path to boost the conductive loss. Meanwhile, SnS nanosheets in the form of flowers with unique semiconductor properties offer a lot of polarization active sites, which encourage polarization loss. Furthermore, by optimizing the ratio of SnS and N-CNTs, the dielectric characteristics and impedance matching of the composites may be efficiently adjusted. The results certify that optimized SnS/N-CNT heterogeneous nanoframeworks exhibit thin thickness, lightweight, and strong absorption characteristics, which are recommended as promising microwave absorbers.