Nano-Raman and Nano-Infrared Imaging of Dimerization\nof 4‑Bromothiophenol on 2D Molybdenum Disulfide and Molybdenum\nDisulfide@Gold Hybrids

Although metal dichalcogenides have unique optical and mechanical\ncharacteristics, they are 2D materials that as catalysts for light-driven\nreactions are yet to be fully understood. In this study, we used atomic\nforce microscopy-infrared (AFM-IR) and tip-enhanced Raman (TER) spectroscopy\nto examine catalytic properties of 2D molybdenum disulfide (MoS2)\nsynthesized by a hydrothermal approach as well as its hybrid with\ngold nanoparticles (MoS2@AuNPs). We found that both MoS2 and MoS2@AuNPs\ndehalogenase and dimerized 4-bromothiophenol (4-BTP) yielded thiophenol\n(TP) and 4,4′-biphenyldithiol (4,4′-BPDT), respectively.\nAlthough an equal yield of TP was observed on both MoS2 and MoS2@AuNPs,\nwe observed a much greater yield of 4,4′-BPDT on MoS2@AuNPs\ncompared with MoS2. These results demonstrated that metal dichalcogenides\nand their plasmonic hybrids could perform catalysis transformations\npreviously evident for plasmonic metals such as gold and silver. Fabrication\nsimplicity of metal dichalcogenides and their low costs open new avenues\nfor synthetic approaches that can be used to develop a novel class\nof catalysts with the desired properties.