Tuning the Photo-electrochemical Performance of Ru^II -Sensitized Two-Dimensional MoS₂

Covalently tethering photosensitizers to catalytically active 1T-MoS₂ surfaces holds great promise for the solar-driven hydrogen evolution reaction (HER). Herein, we report the preparation of two new Ru^II -complex-functionalized MoS₂ hybrids [Ru^II (bpy)₂ (phen)]-MoS₂ and [Ru^II (bpy)₂ (py)Cl]-MoS₂ . The influence of covalent functionalization of chemically exfoliated 1T-MoS₂ with coordinating ligands and Ru^II complexes on the HER activity and photo-electrochemical performance of this dye-sensitized system was studied systematically. We find that the photo-electrochemical performance of this Ru^II -complex-sensitized MoS₂ system is highly dependent on the surface extent of photosensitizers and the catalytic activity of functionalized MoS₂ . The latter was strongly affected by the number and the kind of functional groups. Our results underline the tunability of the photovoltage generation in this dye-sensitized MoS₂ system by manipulation of the surface functionalities, which provides a practical guidance for smart design of future dye-sensitized MoS₂ hydrogen production devices towards improved the photofuel conversion efficiency.