One-pot fabrication of Mo1-xWxS2 alloy nanosheets as SERS substrates with highly Raman enhancement effect and long-term stability

A new Mo 1- x W x S 2 two-dimensional nanosheets were prepared by the one-pot method. After certain Mo atoms in MoS 2 were replaced by W ones in a hydrothermal reduction procedure, Mo 1- x W x S 2 was formed on the Mo foil. Well enhanced Mo 1- x W x S 2 nanosheets were prepared when the sodium tungstate concentration got under control. Various characterizations were carried out, which indicate that Mo 1- x W x S 2 nanosheets with good crystallinity. Compared with MoS 2 , the Raman intensity of Rhodamine 6G (10 −6 M) was amplified by 1.7 times with Mo 1- x W x S 2 nanosheets as the substrate. The characteristic Raman peaks could still be clearly distinguished until the concentration of Rhodamine 6G (R6G), Methylene blue (MB) and Crystal violet (CV) down to 10 −8 , 10 −8 and 10 −7 M, respectively. With abundant edge active sites that facilitate charge transfer, Mo 1- x W x S 2 nanosheets could better enhance SERS signals of target detection molecules and get a good linear relationship exists within the concentration and Raman peak strength. In addition, R6G SERS detection also shows excellent reproducibility and long-term stability of this TMDs SERS substrate.