Armchair shaped polymeric nitrogen N8 chains confined in h-BN matrix at ambient conditions: stability and vibration analysis

Abstract

A new hybrid material comprising of armchair shaped polymeric nitrogen chains (N₈) encapsulated in h-BN matrix is proposed and studied through ab initio calculations. Interestingly, the theoretical results demonstrate that N₈ chains, confined in h-BN matrix, are effectively stabilized at ambient pressure and room temperature. Moreover, N₈ chains can dissociate and release energy at a much milder temperature of 600 K. The confined polymer N₈ unit needs to absorb 0.68 eV energy to span the decomposition energy barrier before decomposing. Further research shows that the charge transfer between N₈ chain and h-BN layer is the stabilizing mechanism of this new hybrid material. And the low dissociation temperature is due to a much smaller amount of charge transfer compared to other confined systems in previous reports. The IR and Raman vibrational analyses suggest that host–guest interactions in the hybrid material influence the vibration modes of both the confined N₈ chain and h-BN layer.