Photochemical reduction of ultrasmall Pt nanoparticles on single-layer transition-metal dichalcogenides for hydrogen evolution reactions

Single-layer TaS2 and TiS2 nanosheets were meticulously synthesized through an electrochemical lithium-intercalation-based exfoliation method. Subsequently, ultrasmall Pt nanoparticles, finely sized between 1.2 and 1.6 nm, were expertly deposited onto these monolayer nanosheets via an environmentally friendly photochemical reduction process. The resulted Pt-TaS2 and Pt-TiS2 composites exhibit hydrogen evolution reaction (HER) activity comparable with commercial Pt/C. Density functional theory calculations reveal that the introduced Pt (111) plane energetically promotes the adsorption of ∗H with an optimal ΔG value of 0.09 eV. Furthermore, these composite materials demonstrate outstanding cycle stability, far exceeding that of Pt/C. This compelling performance underscores the potential of Pt-TaS2 and Pt-TiS2 hybrids as promising alternatives for HER catalysts.