Hydrogen-induced metallicity and strengthening of MoS2

The performed DFT calculations for MoS2 layers with adsorbed and intercalated hydrogen indicate that the atomic hydrogen monolayer makes the surface metallic. The physisorbed H-2 does not affect electronic properties of the MoS2 monolayer, which remains a direct gap semiconductor. Due to forming S-H-S bonds, hydrogen atoms, intercalated into the space between MoS2 layers, increase the interlayer interaction from 0.12 eV to 0.60 eV. The related increase of the stiffness of the Mo-H-Mo layered system is of a primary importance for the interpretation of images of the surface obtained with the Ultrasonic Force Microscopy (Kolosov and Yamanaka, 1993) [42]. (C) 2014 Elsevier B. V. All rights reserved.