Engineering MoSe/WS Hybrids to Replace the Scarce Platinum Electrode for Hydrogen Evolution Reactions and Dye-Sensitized Solar Cells.

In recent times, two-dimensional transition-metal dichalcogenides (TMDs) have become extremely attractive and proficient electrodes for dye-sensitized solar cells (DSSCs) and water electrolysis hydrogen evolution as alternatives to the scarce metal platinum (Pt). The active TMD molybdenum selenide (MoSe) and tungsten disulfide (WS) are inspiring systems owing to their abundance of active sulfur and selenium sites, but their outputs are lacking due to their inactive basal planes and ineffective transport behavior. In this work, van der Waals interrelated MoSe/WS hybrid structures were constructed on conducting glass substrates by chemicophysical methodologies. For the first time, the constructed MoSe/WS structures were effectively used as a counter electrode for DSSCs and an active electrode for hydrogen evolution to replace the nonabundant Pt. The assembled DSSCs using the designed MoSe/WS heterostructure counter electrode provided a superior power-conversion efficiency of 9.92% and a photocurrent density of 23.10 mA·cm, unmatchable by most of the TMD-based structures. The MoSe/WS heterostructure displayed excellent electrocatalytic hydrogen evolution behavior with a 75 mV overpotential to drive a 10 mA·cm current density, a 60 mV·dec Tafel slope, and an over 20 h durable process in an acidic medium. The results demonstrated the advantages of the MoSe/WS hybrid development for generating interfacial transport and active facet distribution and enriching the electrocatalytic activity for DSSCs and the water-splitting hydrogen evolution process.