Multilevel Theoretical Screening of Novel Two-Dimensional MAZ Family for Hydrogen Evolution.

The synthesis of 2D MoSiN marked the birth of a new family of 2D MAZ materials, whose potential applications are expected to sweep the field of nanoscale devices and catalysis in the future. In this work, we propose a multilevel screening workflow to systematically explore the mechanic stabilities, electronic properties, and hydrogen evolution performances of the 2D MAZ family, among which seven stable, metallic, and highly active 2D MAZ monolayers (2H-α-VGeN, 2H-α-NbGeN, 2H-α-TaGeN, 2H-α-NbSiN, 2H-β-VGeN, 2H-β-NbGeN, and 2H-β-TiGeP) are predicted as promising hydrogen evolution reaction (HER) catalysts with near-zero hydrogen adsorption free energy (Δ). The lowest unoccupied state energy () of the MAZ basal plane is identified as a concise descriptor to influence the electron filling and eventually determine its Δ. The criteria of -6.0 < < -5.6 eV is confirmed as the HER active window to explore novel HER catalysts. In particular, group-VI-terminated MAZ basal planes have a higher (> -5.6 eV), which leads to weak H adsorption and poor HER activities accordingly.