Uncovering the missing piece of unsaturated two-dimensional phosphorus: a theoretical approach

Abstract

Breakthroughs in the synthesis of graphyne have stimulated vast interest in the design of new unsaturated 2D materials, mainly via the elemental replacement of graphyne, for promising applications. Here, a novel group VA counterpart of graphyne, namely phosphoryne, is reported based on first-principles calculations. Computed binding energies, phonon dispersions, and elastic stiffness coefficients of phosphoryne allotropes exhibit the energetic, kinetic, and mechanical stabilities. The 2D semiconducting phosphoryne monolayers have adaptable bandgaps from 1.38 to 1.79 eV, which are tunable under biaxial strain. The sp² phosphorus has been demonstrated, using DFT and AIMD simulations with a small overpotential, to have more useful sites for the HER. Combining the intrinsic unsaturated binding character, appropriate bandgaps, and full spectrum adsorption abilities, phosphoryne monolayers are promising candidates to act as substrates for electronic and photocatalytic nanodevices, and this may encourage future researchers to create them in the future.