Electrospun Pt-doped SnO2 nanofibers enabling sensitive and selective NO2 detection

Pristine SnO 2 is extensively employed in gas sensing applications owing to its excellent stability in acidic and alkaline environments; however, its sensitivity and selectivity still require improvement. This study reports the fabrication of Pt-doped SnO 2 (Pt-SnO 2 ) nanofibers via electrospinning and subsequent calcination, along with the optimization of Pt doping concentration for efficient NO 2 detection. The optimized sensor (0.5 Pt-SnO 2 ) displays significantly enhanced sensing performance relative to pristine SnO 2 , which is primarily ascribed to the elevated oxygen vacancy density and enlarged specific surface area. This sensor exhibits an approximately 20-fold increase in response to 100 ppm NO 2 compared with pristine SnO 2 and achieves a minimum detectable concentration of 5 ppb. The 0.5 Pt-SnO 2 sensor also demonstrates satisfactory response and recovery behavior over a wide detection span, along with remarkably high selectivity, excellent repeatability, and good long-term stability. Furthermore, first-principles calculations confirm that Pt-doped SnO 2 possesses higher adsorption energy and much greater charge transfer than pristine SnO 2 . This work presents a facile and robust strategy to enhance the NO 2 sensing performance of SnO 2 , with potential applications in industry and modern agriculture.