Self-Templated Growth of Vertically Aligned 2H-1T MoS₂ for Efficient Electrocatalytic Hydrogen Evolution

Semiconductor heterostructures of two-dimensional (2D) transition metal disulfide (TMD) have opened up approaches toward the integration of each function and implementations in novel energy and electronic devices. However, engineering TMD-based homostructures with tailored properties is still challenging. Herein, we demonstrate a solution-processed growth of vertically aligned 1T-MoS₂ using liquid-phase exfoliated 2H-MoS₂ as self-templates. The unique MoS₂-based homostructures not only provide more exposed active sites in the edge and basal plane for the electrocatalytic hydrogen evolution reaction (HER) but also improve the mass transfer due to the introduction of high packing porosity. The resultant all-MoS₂ electrocatalysts with an integration of polymorphous MoS₂ nanostructures exhibit a superior HER activity with a low potential of 203 mV at 10 mA cm^-2, a small Tafel slope of 60 mV dec^-1, and a remarkable cyclic stability. This work thus provides a simple and efficient route for the creation of unprecedented MoS₂-based homostructured materials with exciting properties, especially as an inexpensive alternative to platinum catalysts in electrochemical hydrogen evolution production.