First-principles study of the catalytic properties of Co-doped molybdenum disulfide nanoribbons for the hydrogen evolution reaction.

Molybdenum disulfide has attracted significant research attention as a nanocatalyst for hydrogen evolution reaction. In this study, the effects of nanoribbons on the catalytic performance of molybdenum disulfide in the hydrogen evolution reaction are evaluated via the density functional theory. Co is considered to be an effective promoter of Mo-based catalysts. Thus, the promotion of the Mo-edge was studied here in a number of Co-substituted surface models. The results show that the electronic structure of the molybdenum disulfide nanoribbons changed after doping with Co atoms; this change significantly reduced the Gibbs free energy of the hydrogen evolution reaction and improved the reaction activity. In addition, the effects of stress regulation on the catalyst were analyzed. Tensile and compressive stresses were applied to the catalyst in the x direction. The results indicate that the distance between atoms changed owing to the effects of stress, and changes were also observed in the electronic properties. The insights obtained from this study will be helpful to further improve the activity of catalysts. [ABSTRACT FROM AUTHOR]