Rosette-like MoS 2 nanoflowers as highly active and stable electrodes for hydrogen evolution reactions and supercapacitors.

MoS 2 is regarded as one of the cost-effective materials for many important applications. In this work, we report a simple one-step hydrothermal method for the directed synthesis of a rosette-like MoS 2 nanoflower modified electrode without using adhesion agents. Interestingly, owing to the hierarchical structures, the as-prepared MoS 2 -based electrode exhibits significantly enhanced performance for both the hydrogen evolution reaction in acidic environments and supercapacitors. When used in the hydrogen evolution reaction, the electrode shows a low overpotential of ∼0.25 V at 10 mA cm -2 , a Tafel slope of ∼71.2 mV per decade, and long-term durability over 20 h of hydrogen evolution reaction operation at 10 mV cm -2 . In addition, as a supercapacitor electrode, it exhibits a good capacity of 137 mF cm -2 at a current density of 10 mA cm -2 and excellent stability in 1 M H 2 SO 4 at a scan rate of 50 mV s -1 . The outstanding performances of the as-prepared materials may be ascribed to the unique 3D architectures of the rosette-like MoS 2 nanoflowers. This work could provide a strategy to explore low-cost and highly efficient electrocatalysts with desired nanostructures for the hydrogen evolution reaction and supercapacitors applications.