Vertically oriented MoS2 nanosheets with vast exposed edges for enhanced electrocatalytic hydrogen evolution

Molybdenum disulfide (MoS 2 ), a typical two-dimensional transition metal dichalcogenides, is a promising candidate for electrochemical water splitting catalysis due to its ultrahigh special area and highly exposed active edge sites. The main challenges restricted the wider application for MoS 2 -based nanomaterials are the complex preparation process and the high overpotential. Here, we design a novel and facile sealed vessel to synthesize vertical oriented MoS 2 nanosheets electrocatalyst with vast exposed edges. Benefiting from the unique vertically-oriented structural and compositional characteristics, the MoS 2 nanosheets with 10-20 layers exhibits superior hydrogen evolution reaction (HER) performance with a small overpotential of 135.2 mV at a current density of 10 mA∙cm -2 and low Tafel slope of 82.5 mV∙dec -1 as well as extraordinary catalytic stability over 5000 cycles. Importantly, the sealed vessel reactor system may open up a versatile and potential synthetic way to construct various morphologies and structure of metal dichalcogenides for high-performance energy storage and conversions devices.