Oxygen and hydroxyl adsorption on MS2 (M=Mo,W,Hf monolayers): A first-principles molecular dynamics study

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim In this paper, we study the oxygen and hydroxyl adsorption on both pristine and S deficient MS2 (M = Mo, W, Hf) monolayers, using first-principles molecular dynamics calculations. Our simulations reveal that single-layer HfS2 suffers severely from oxidation, which results in the formation of strong Hf–O bonds, likely degrading the transport properties of the material. Oxygen adsorption on S deficient monolayers acts as a passivation mechanism, both ”structurally” by saturating the dangling bonds of neighboring metal atoms and ”electronically” by removing the S vacancy induced gap states. Hydroxyl adsorption on pristine monolayers generates spin-polarized gap states, and for HfS2 in particular, causes the Fermi level pinning close to the conduction band edge.status: publishe