Decoration of Silver Nanoparticles on WS₂-WO₃ Nanosheets: Implications for Surface-Enhanced Resonance Raman...

This study investigates the chemical and structural modifications of vertically aligned tungsten disulfide-tungsten trioxide (WS₂-WO₃) nanosheets decorated with silver nanoparticles (Ag(NPs)) under nitrogen plasma conditions. The synthesized vertically aligned WS₂-WO₃ nanosheets were functionalized through direct-current (DC) magnetron sputtering, forming silver-decorated samples. Structural changes, as well as the size and distribution of Ag(NPs), were characterized using scanning electron microscopy (SEM). Chemical state analysis was conducted via X-ray photoelectron spectroscopy (XPS), while Raman spectroscopy was employed to investigate vibrational modes. The findings confirmed the successful decoration of Ag(NPs) and identified unexpected compound transformations that were dependent on the duration of functionalization. The synthesized and functionalized samples were evaluated for their sensing capabilities towards Rhodamine B (RhB) through surface-enhanced resonance Raman scattering (SERRS). This study discusses the impact of substrate morphology and the shape and size of nanoparticles on the enhancement of SERRS mechanisms, achieving an enhancement factor (EF) of approximately 1.6 × 10⁶ and a limit of detection (LOD) of 10^-9 M.