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 H-2 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 H-2 evolution and ultrahigh active site density simultaneously. The calculated kinetic barrier of H-2 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.