MoS 2 /graphene van der Waals heterojunctions combined with two-layered Au NP for SERS and catalysis analyse

Abstract

MoS 2 -plasmonic hybrid platforms have attracted significant interest in surface-enhanced Raman scattering (SERS) and plasmon-driven photocatalysis. However, direct contact between the metal and MoS 2 creates strain that deteriorates the electron transport across the metal/ MoS 2 interfaces, which would affect the SERS effect and the catalytic performance. Here, the MoS 2 /graphene van der Waals heterojunctions (vdWHs) were fabricated and combined with two-layered gold nanoparticles (Au NP) for SERS and plasmon-driven photocatalysis analyse. The graphene film is introduced to provide an effective buffer layer between Au NP and MoS 2 , which not only eliminates the inhomogeneous contact on MoS 2 but also benefits the electron transfer. The substrate exhibits excellent SERS capability realizing ultra-sensitive detection for 4-pyridinethiol molecules. Also, the surface catalytic reaction of p-nitrothiophenol (PNTP) to p,p-dimercaptobenzene (DMAB) conversion was in situ monitored, demonstrating that the vdWHs-plasmonic hybrid could effectively accelerate reaction process. The mechanism of the SERS and catalytic behaviors are investigated via experiments combined with theoretical simulations (finite element method and quantum chemical calculations).