Theoretical studies of copper azide/graphene nanocomposites based on density functional theory

Graphene has been designed as substrate to improve the sensitivity characteristics of Cu(N
3
)
2
, lots of research findings have supported this strategy. However, the stabilization mechanism of Cu(N
3
)
2
/graphene nanocomposite has not yet been revealed. In this work, based on density functional theory (DFT), the molecular structure, electrostatic potential distribution, energy band and density of states of the two different structure models of Cu(N
3
)
2
and Cu(N
3
)
2
/graphene are compared and analyzed. The results show that, under the influence of graphene, the Cu-N bond length adjacent to both sides of Cu atoms in nanocomposites increases significantly, and the N-N bond length adjacent to Cu-N becomes shorter and more uniform. The electron cloud density between N atoms increases, and the bond energy increases accordingly; the average electrostatic potential of nanocomposites distributes homogeneous (variance decreased from +2.47 to +0.53), which is not conducive to electronic excitation, making Cu(N
3
)
2
more stable; graphene in nanocomposites is prone to lose electrons and transfer to Cu(N
3
)
2
, and the electron density of Cu(N
3
)
2
/graphene is evenly distributed, which is beneficial to the improvement of the sensitivity of the primary explosives.