Surface-Enhanced Raman Scattering in MoS2 based 2D materials: Synthesis and Characterization

• Autores: Lei Chen
• Directores de la Tesis: Maurizio Prato (dir. tes.), Huilei Hou (dir. tes.)
• Lectura: En la Universidad del País Vasco - Euskal Herriko Unibertsitatea ( España ) en 2024
• Idioma: inglés
• Número de páginas: 182
• Programa de doctorado: Programa de Doctorado en Química Aplicada y Materiales Poliméricos por la Universidad del País Vasco/Euskal Herriko Unibertsitatea
• Materias:
  • Química
• Enlaces
  • Tesis en acceso abierto en: ADDI
• Resumen

  • In this study, we investigated the influence of n- and p-type doping of exfoliated MoS2 (exMoS2) hybrids on the SERS performance, employing Rhodamine 6G (R6G) as a probe molecule. We demonstrate that n-doped exMoS2 hybrids exhibit enhanced SERS intensities while p-doping resulted in inhibited SERS enhancement. In the second project, we report how to modulate the SERS response of 2D materials. First, we demonstrate that SERS based on graphene materials is inversely proportional to the functionalization degree. For graphene/MoS2 vdW heterostructures, the SERS enhancement is dominated by the vdW interaction between graphene and MoS2. A shorter interlayer distance, with stronger vdW interactions, improves the dipole-dipole interaction and the charge transfer, increasing the Raman enhancement. Moreover, the SERS intensity of graphene/MoS2 vdW heterostructures varies rapidly when the interlayer distances are less than 0.6 nm, while they vary less at interlayer distances longer than 0.6 nm. We also present a novel strategy for synthesizing covalently bonded MoS2-graphene heterostructures using organic linkers with two anchor sites at a low cost. Our covalent heterostructures exhibit a more homogeneously alternating structure than the corresponding randomly alternating structure of vdW heterostructures, as confirmed by SERS measurements. Moreover, different linkers can be used to adjust the interlayer distance between graphene and MoS2, leading to significant impacts on their optical and electrochemical properties.