Adsorption and Detection of 2,4,6-Trinitrotoluene by New Two-Dimensional BCN Monolayers: A First-Principles Study

Abstract

Three predicted new two-dimensional (2D) boron carbon nitrogen (BCN) structures, named B8C2N8, B6C6N6-1, and B6C6N6-2, are investigated theoretically. The stability and electronic properties of the three structures are explored. The results reveal that three 2D BCN structures are dynamically, thermodynamically, and mechanically stable. B8C2N8 is a direct semiconductor with a band gap of 1.76 eV, B6C6N6-1 is an indirect semiconductor with a band gap of 0.21 eV, and B6C6N6-2 exhibits metallic properties. B6C6N6-1 shows a transition from semiconductor to conductor under an external strain. The large adsorption energies of TNT adsorbed on BCN reveal that it is feasible to use 2D BCN materials to adsorb TNT. Among the three BCNs, due to the largest band gap variation and the largest charge transfer amounts, B8C2N8 has an outstanding performance in terms of the adsorption of TNT and is expected to be used to detect TNT or other nitro molecules.