Modulating band structure of MoO3 via W-doped for enhanced photo-induced charge transfer and SERS detection

Surface-enhanced Raman spectroscopy (SERS) of MoO 3 semiconductors leverages charge-transfer (CT) pathways to achieve highly sensitive detection of toxic molecules, demonstrating significant potential for multiple applications. However, insufficient CT pathways and efficiencies are key factors limiting the development. In this work, W-doped MoO 3 substrates with different doping ratio were prepared using double-target magnetron sputtering method to increase the CT pathway formation. UV–Vis and UPS analyses indicate that the enhancement of SERS activity was mainly due to the narrowing of the optical bandgap and the optimization of band edge positions, which promoted the formation of photo induced charge transfer pathways. The W-doped MoO 3 substrates significantly elevated the SERS response by several orders of magnitude compared to the original value, achieving an enhancement factor (EF) of CV up to 1.31 × 10 6 . Importantly, the W-doped MoO 3 substrates have proven capable of simultaneously detecting two types of pollutant molecules in river water affected by industrial emissions, highlighting their practical application potential in environmental monitoring.