Ag-SnO₂ nanofibers with lattice oxygen activation for high performance triethylamine gas sensor

TEA is a highly flammable and neurotoxic volatile organic compound; prolonged exposure can lead to emphysema and even immediate death, making the development of rapid, highly responsive TEA gas sensors an urgent priority. Although tin dioxide (SnO₂)-based sensors have been extensively studied, they suffer from low sensitivity and high operating temperatures. In this study, silver-loaded tin dioxide nanofibers (Ag-SnO₂ NFs) with a porous hollow structure were fabricated using electrospinning combined with in-situ reduction technology. The Schottky junction at the Ag-SnO₂ interface triggers interfacial electron redistribution, thereby activating lattice oxygen (O_L) in SnO₂ and converting it into adsorbed oxygen species, which enhances the gas-sensing performance for TEA. At 200℃, the AS-2 sensor exhibited a response value of 2163.6 for 100 ppm of TEA, which is 79 times that of pure SnO₂, and demonstrated fast response and recovery times (48 s/44 s). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations further elucidated this mechanism. This study provides a new mechanistic insight into how noble metal modification activates lattice oxygen and converts it into adsorbed oxygen to enhance gas sensing performance, offering rational design principles for advanced gas sensors targeting harmful volatile compounds.