Template-Grown MoS2 Nanowires Catalyze the Hydrogen Evolution Reaction: Ultralow Kinetic Barriers with High Active Site Density

Molybdenum disulfide (MoS2) is considered to be one of the most promising low-cost catalysts for the hydrogen evolution reaction (HER). So far, the limited active sites and high kinetic barriers for H2 evolution still impede its practical application in electrochemical water splitting. In this work, on the basis of comprehensive first-principles calculations, we predict that the recently produced template-grown MoS2 nanowires (NWs) on Au(755) surfaces have both ultralow kinetic barriers for H2 evolution and ultrahigh active site density simultaneously. The calculated kinetic barrier of H2 evolution through the Tafel mechanism is only 0.49 eV on the Mo edges, making the Volmer–Tafel mechanism operative, and the Tafel slope can be as low as 30 mV/dec. Through substitution of the Au(755) substrate with non-noble metals, such as Ni(755) and Cu(755), the activity can be maintained. This work provides a possible way to achieve the ultrahigh HER activity of MoS2-based catalysts.