Preparation of Pt-, Ni- and Cr-Decorated SnO 2 Tubular Nanofibers and Their Gas Sensing Properties

The Pt-, Ni- and Cr-decorated tubular SnO 2 nanofibers for gas sensors were prepared by the electrospinning of polyvinylpyrrolidone (PVP) nanofibers containing Pt, Ni, and Cr precursors, the sputtering of SnO 2 on the electrospun PVP nanofibers, and the removal of sacrificial PVP parts by heat treatment at 600 o C for 2 h. Pt-decorated tubular SnO 2 nanofibers showed high response ( R a /R g =210.5, R g : resistance in gas, R a : resistance in air) to 5 ppm C 2 H 5 OH at 350 o C with negligible cross-responses to other interference gases (5 ppm trimethylamine, NH 3 , HCHO, p -xylene, toluene and benzene). Cr-decorated tubular SnO 2 nanofibers showed the selective detection of p-xylene at 400 o C. In contrast, no significant selectivity to a specific gas was found in Ni-decorated tubular SnO 2 nanofibers. The selective and sensitive detection of gases using Pt-decorated and Cr-decorated tubular SnO 2 nanofibers were discussed in relation to the cat-alytic promotion of gas sensing reaction.