▎ 摘　　要

Transition metal dichalcogenides are rising candidates for the replacement of Pt catalysts in water splitting. In this theoretical study we focus on the hydrogen evolution reaction part of this process and on how hydrogen (H) interacts with MoS2 nanostructures, free-standing or positioned on a graphene substrate. Density functional theory calculations confirm the stability of such nanostructures and our results for H on several configurations, from 2D infinite monolayers to quasi-1D MoS2 ribbons and quasi-0D MoS2 flakes, are presented. We calculate the adsorption energy of H atoms on various sites of the MoS2 nanostructures, notably at Mo and S active edges. Comparing free-standing and MoS2/graphene hybrid systems we find that the effect of the support on the adsorption of H on MoS2 nanostructures is quite significant when the substrate induces strain. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim