Expanding the landscape of anti-MoS2 monolayers: computational exploration of stability and multifaceted properties across the periodic table

Inspired by the distinctive structural and electronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDs), we conducted comprehensive high-throughput first-principles computations to screen stable 2D chalcogenides X2T (X = transition metals Sc–Hg, totally 29 and main group elements Li–Ba, totally 37; T = S, Se, and Te) with anti-MoS2 configurations in both 1T and 2H phases. Among 396 evaluated candidates, the selected X2T monolayers (X = Sc, Fe, Y, Zr, Nb, Hf, Ta, IA elements Li–Fr, IIA elements Ca–Ra, N, In, Tl, and Te; T = S, Se, or Te) demonstrate outstanding thermodynamic, dynamic, mechanical properties, and thermal stabilities in 1T/1T′ or 2H phases. These anti-MoS2 variants exhibit diverse characteristics, serving as nonmagnetic/magnetic metals or nonmagnetic/antiferromagnetic semiconductors, often surpassing MoS2 in Young's modulus and/or displaying negative Poisson's ratios. Transition-metal-based monolayers show susceptibility to O2 oxidization, and some show high N2 dissociation activity. Oxygen/nitrogen-terminations can quench TM magnetism and increase band-gaps over their pristine counterparts. Notably, the 2H-Fe2S monolayer maintains robust antiferromagnetism upon O-termination. Moreover, TM-based X2T sheets demonstrate promise as efficient electrocatalysts for hydrogen evolution reactions. This study expands the diversity of 2D materials with new members and novel functional properties and broadens their potential applications.