Date Published: April 23, 2016
Publisher: John Wiley and Sons Inc.
Author(s): Xu Zhang, Xudong Zhao, Dihua Wu, Yu Jing, Zhen Zhou.
The 2D material single‐layer MnPSe3 would be a promising photocatalyst for water splitting, as indicated by the proper positions of band edges, strong absorption in visible‐light spectrum, broad applicability (pH = 0 – 7), and high carrier mobility.
Our first‐principles computations based on density functional theory (DFT) were performed with a plan‐wave basis set as implemented in the Vienna ab initio simulation package (VASP).25 The projector augmented wave (PAW) was used to describe the ion–electron interaction.26 The generalized gradient approximation (GGA) expressed by the functional of Perdew, Burke, and Ernzerhof (PBE).27 A 500 eV cutoff was used for the plane‐wave basis set. The DFT‐D3 method with Becke–Jonson damping was adopted to accurately account for the van der Waals force for weak interactions.28 A Monkhorst–Pack k‐point mesh of 7 × 7 × 1 was used for 2D sheet, 7 × 7 × 2 for selenide bulk and 6 × 3 × 5 for sulfide bulk. To study 2D systems under periodic boundary conditions (PBC), a vacuum space with at least 15 Å was inserted between the MPX3 sheets and the periodically repeated images. Moreover, considering that GGA functional systematically underestimates the band gaps,29 we computed the band structures with the HSE06 hybrid functional.30 The computation of the phonon dispersion spectrums was calculated through CASTEP code with finite displacement method as implemented in Materials Studio.31