Facile synthesis of MoS2 nanosheet-silver nanoparticles composite for surface enhanced Raman scattering and electrochemical activity

Herein MoS2 nanosheet/silver nanoparticles (MoS2/AgNPs) composite is fabricated according to a wet chemistry procedure. The morphology of the composite is characterized by transmission electron microscopy, atomic force microscopy, showing that the AgNPs randomly distribute on the MoS2 nanosheet. Enhanced Raman spectrum of 2-mercaptobenzimidazole (MBI) on prepared MoS2/AgNPs substrate is obtained with excitation at 632.8 nm. It has been found that MBI is chemisorbed on the Ag surface as thiol forms through the sulphur and nitrogen atoms and the molecular plane indicates a perpendicular orientation with respect to the Ag surface. The obtained composite exhibits a high-quality surface-enhanced Raman scattering (SERS) activity which may offer great potential applications for low cost, reliable and selective SERS sensing. Furthermore, the electrochemical performances of MoS2/AgNPs are studied by cyclic voltammetry, displaying an electrochemically irreversible behavior.