In-situ wet tearing based subnanometer MoSeS for efficient hydrogen evolution

The development of ultrasmall transition-metal dichalcogenide (such as MoS2, MoSe2) nanostructures is an efficient strategy to increase the active edge sites and overall performance for hydrogen evolution reaction. Here, we report an in-situ tearing strategy to produce the carbon nanotube supported subnanometer ternary MoSeS (denoted as CNTs@NiSe@MoSeS) for efficient hydrogen evolution. Large (18.3 ± 1.1 nm in length) multilayer MoS2 sheets grown on Ni(OH)2 thin film are torn into subnanometer (5.2 ± 0.7 nm in length) MoSeS via a subsequent selenization progress, along with the transformation of Ni(OH)2 thin film into small NiSe nanoplates. The resulting nanocomposite exhibits abundant active edge sites, outstanding 10,000-cycle stability and ultrahigh activity with a low overpotential of 189 mV at a high current density of 200 mA cm−2 toward hydrogen evolution.