Ti3BN monolayer: the MXene-like material predicted by first-principles calculations

Abstract

The discovery of graphene and other two-dimensional (2D) materials has set the foundation for exploring and designing novel single layered sheets. The family of 2D materials encompasses a wide selection of compositions including almost all the elements of the periodic table and they have the potential to play a fundamental role in the future of electronics, composite materials and energy technology. Therefore, searching for new 2D materials is a big challenge in materials science. In this work, we theoretically designed a monolayer of Ti₃BN following the strategy of “atomic transmutation”. The Ti₃BN monolayer can be considered as three Ti-atomic layers being interleaved with one N-atomic layer and one B-atomic layer, in the sequence of Ti₁–N–Ti₂–B–Ti₃. The moderate cohesive energy, positive phonon frequencies and high melting point are the best guarantees for good stability of Ti₃BN. Based on a global minimum structures search using the particle-swarm optimization (PSO) method, Ti₃BN is the lowest energy structure in 2D space, which holds great promise for the realization of layered Ti₃BN in experiment. Based on density functional theory (DFT) calculations, Ti₃BN is intrinsically metallic and its electronic properties can be modulated by varying the surface groups, such as OH or F-termination. If realized in experiment, it may find applications in many aspects.