Selectivity enhancement of SnO 2 nanofiber gas sensors by functionalization with Pt nanocatalysts and manipulation of the operation temperature a b s t r a c t We report on facile synthesis of SnO 2 nanofibers (NFs) functionalized by Pt nanoparticles (NPs) with var-ious loading contents (0.05–0.4 wt%) and their gas response toward H 2 , NO 2 , NH 3 , CO, and SO 2 gases as a function of the operation temperature (100–450 • C) and gas concentration (0.125–2.5 ppm). Mesoporous SnO 2 NFs with large surface-to-volume ratio, which facilitates sensitive gas response, were synthesized by electrospinning followed by subsequent calcination at 500 • C for 2 h. Colloidal Pt NPs synthesized by simple polyol method were immobilized on SnO 2 NFs as a catalytic sensitizer to H 2 oxidation. The gas sensing properties and response kinetics were significantly affected by the Pt NPs and the operation tem-perature. It was found that 0.1 wt% Pt-loaded SnO 2 sensor showed the highest H 2 response (I gas /I air = 16.6 at 2.5 ppm) at 300 • C. A remarkably high NO 2 response (I air /I gas = 57.0 at 2.5 ppm) was achieved in the case of pristine SnO 2 sensor at 150 • C. This work demonstrates that sensitive and selective detection of H 2 and NO 2 gases with negligible cross-response to interfering gases such as NH 3 , CO, and SO 2 can be obtained by decoration with Pt NPs on metal oxide NFs in conjunction with manipulation of the operation temperature.