Self-Assembled MoWO Aerogel from Ultrathin Nanowires for Highly Sensitive Surface-Enhanced Raman Spectroscopy

In the realm of surface-enhanced Raman spectroscopy (SERS), the structure of Raman scattering substrate is crucial for determining the detection’s sensitivity and stability. In this work, a combined sol–gel, hydrothermal, and freeze-drying strategy is proposed to prepare MoWO aerogel self-assembled from ultrathin nanowires with a diameter of about 2 nm. The MoWO aerogel has high surface area, abundant oxygen vacancies, and a narrow bandgap. Evaluated as an effective substrate for SERS applications, the MoWO aerogel exhibits pronounced localized surface plasmon resonance at 682 nm and possesses a narrowed bandgap of 2.12 eV. The detection limit of MoWO aerogel for the probe molecule Rhodamine 6G (R6G) is as low as 1 × 10 –10 M, with an enhancement factor (EF) as high as 7.2 × 10 6 . Significantly, it still maintains its intact structure and high SERS activity under long-term high-temperature treatment and strong laser irradiation, demonstrating exceptional chemical stability.