Hierarchical WO3 Nanofibers for Ultrasensitive Gas Detection via Pore-Creating and Inner Anchoring Silver Nanoparticles

Ultrasensitive detection of triethylamine (TEA), a characteristic volatile in seafood, is particularly important for food safety and human health. The preparation of nanosensing materials with special structures is an important step toward high-performance TEA detection. This study introduces a novel method of loading noble metal catalysts onto the inner walls of WO₃ macroporous nanofibers (MNFs) to prepare high-performance TEA sensing materials by using core-shell nanospheres with glucose-coated Ag particles as sacrificial templates. After high-temperature calcination, WO₃ MNFs loaded with Ag particles on the inner wall (Ag-WO₃ MNFs) were obtained by decomposition of organic components and oxidation of W precursors. The abundant porous structure, large number of oxygen vacancies and strong sensitizing effect of Ag particles give Ag-WO₃ MNFs excellent sensing performance. Gas sensing measurements reveal that 1.5% Ag-WO₃-based sensor responds to 1 ppm TEA with a response time of 1 s, a response value as high as 1054.17 (R_a/R_g), and a low detection limit (12.8 ppb) at 185 °C. The adsorption process of gas molecules on the surface of Ag-WO₃ MNFs is revealed using density-functional theory (DFT) calculations. The integration of this distinctive design concept with an in-depth mechanistic investigation offers a novel strategy for engineering high-performance TEA sensing materials.