Few-Layer Borophene Prepared by Mechanical Resonance and Its Application in Terahertz Shielding.

Once two-dimensional boron-based materials were forecasted, their excellent physical and chemical properties have realized attractive application value in the field of materials science. However, borophene could not exist independently and stably in nature. Molecular beam epitaxy is the only way being used currently for the preparation of borophene, which has low yield and harsh experimental installation conditions. Here, we propose the theory that few-layer borophene supported by silver nanoparticles can exist stably and large-scale preparation of few-layer borophene can be performed by mechanical resonance first. We have revealed that the structure of the prepared borophene is α-sheet and its thickness is less than 4 nm. The oxidation rate of borophene from the experiment is about 0.19, which indicates that the few-layer borophene possesses good structure stability. We have also studied the structure stability of borophene on silver nanoparticles by first principles calculation. The calculation proves that few-layer borophene can exist stably supported with silver nanoparticles. Furthermore, the terahertz shielding and stealth performance of the few-layer borophene have been explored. The maximum terahertz shielding effectiveness value of the prepared material could reach up to 50 and 21.5 dB for the reflection loss value in the broadband range of 0.1-2.7 THz. The large-scale preparation of few-layer borophene through the mechanical method makes it possible to study the properties of borophene and achieve low-cost large-scale applications, such as the study of terahertz shielding and stealth performance in the article, which facilitates the lightweight material design for terahertz shielding and stealth.