Doping induced band-gap shrinkage to modify electronic structure of MoS2 for organic wastewater management

Abstract

MoS2, with its high specific surface area and tunable electronic structure, has received much interest in the fields of sensing and environmental remediation. Nevertheless, pure MoS2 has the disadvantages of easy aggregation and the high electron-hole pairs complexity, which affects its SERS and photocatalytic performance. In this work, band-gap shrinkage strategy was used to improve MoS2 performance for SERS and photocatalytic applications. It exhibited high SERS activity (enhancement factor (EF) = 3.61 × 108), great stability (4 mth), broad universality (CV, CR and R6G), and excellent reusability (recover 95% after 5 cycles). In addition, the interfacial dipole-dipole interaction and charge transfer (CT) process caused by doping Ru together enhance the SERS sensitivity, and the limit of detection of CV is down to 10-11 M. The degradation rate of 10-5 M CV was up to 99% after 60 min of Ru-MoS2 photocatalytic degradation under visible light. This study investigated the effect of doping-induced bandgap shrinkage on charge transfer (CT), providing new insights into improving the sensitivity of semiconductors SERS substrates for efficient low-concentration SERS detection and low-cost sustainable wastewater remediation.