Enhanced electromagnetic wave absorption performance of ZnO/N-doped carbon microspheres in 2-18 GHz

The properties of popular absorbing materials include low thickness, lightweight, a wide frequency range of absorption, and a significant absorption capacity. However, synthesizing a material that contains all these properties remain a considerable challenge. In this manuscript, Zn, N, O-doped microspheres precursors were innovatively synthesized using the one-pot method, which was efficient and simple. Zn, N, O-doped carbon composites (ZnO/N-CNs) were synthesized by heating precursors in an Ar atmosphere. The electromagnetic wave absorption (EMWA) performances for the composites were modified by altering the calcination temperature of the precursors. As a result, the performance of the ZnO/N-CNs calcined at 700 C (ZnO/N-CNs-700) in electromagnetic wave absorption (EMWA) was outstanding. The effective absorption bandwidth (EAB) attained 5.68 GHz (12.32-18 GHz, 2.08 mm), while the minimum reflection loss (RLmin) achieved -44.6 dB (12.24 GHz, 2.5 mm). The synergistic interaction of the porous structure, ZnO/C heterostructure, ZnO particles, carbon, and nitrogen was responsible for the superior EMWA properties of ZnO/N-CNs composites. Therefore, the composites exhibited improved interface and dipole polarization loss, conduction loss, multiple reflection and scattering, and impedance matching. This technique made it possible to mass-produce brand-new N-doped carbon-based composites, which had effective EMWA performance. This article suggested a practical method for creating dielectric wave-absorbing composites with excellent all-around performances.

Automated summary

In this study, Zn, N, O-doped microspheres precursors were synthesized using a one-pot method and Zn, N, O-doped carbon composites (ZnO/N-CNs) were obtained by heating the precursors in an Ar atmosphere. The electromagnetic wave absorption (EMWA) performances of the composites were modified by changing the calcination temperature of the precursors. The ZnO/N-CNs calcined at 700°C showed outstanding EMWA properties, making it possible to mass-produce new N-doped carbon-based composites with effective EMWA performance, and providing a practical method for creating dielectric wave-absorbing composites with excellent all-around performances.