The enhanced dielectric property of the graphene composite anchored with non-planar iron single-atoms
Yanan Shi, Bei Li, Xinyu Jiang, Xiaoli Zhang, Xiaoli Zhang, Xitian Zhang, Xitian Zhang, Yujin Chen, Chunling Zhu
Abstract
The understanding of the relationships between the coordination configuration of single-atoms (SAs) and their properties remains a great challenge. In this manuscript, a facile method is developed to construct Fe-SAs on onion-like nitrogen-doped nanocarbons supported by graphene (ONCG). In contrast to the symmetrical planar Fe–N4 moieties, the Fe-SAs coordinated with N atoms are located above the plane of the curved graphene and exhibited antenna-like structures. The ONCG with non-planar Fe–N4 moieties possesses greatly increased dielectric loss property compared to their counterparts with symmetrical planar Fe-SAs. In-depth theoretical calculations reveal that the unique geometric structure of the non-planar Fe-SAs improves both conduction and polarization losses significantly, which is attributed to the increased dielectric property. The increased dielectric property endows Fe-SAs@ONCG with an excellent electromagnetic wave absorption at a low filler ratio of 10 wt. %. Our results describe an efficient way for the development of non-planar SAs for dielectric applications.