Highly Sensitive and Selective Gas Sensors Using Catalyst-Loaded SnO₂Nanowires

Abstract

Ag-and Pd-loaded SnO 2 nanowire network sensors were prepared by the growth of SnO 2 nanowires via thermal evaporation, the coating of slurry containing SnO 2 nanowires, and dropping of a droplet containing Ag or Pd nanoparticles, and subsequent heat treatment. All the pristine, Pd-loaded and Ag-loaded SnO 2 nanowire networks showed the selective detection of C 2 H 5 OH with low cross-responses to CO, H 2 , C 3 H 8 , and NH 3 . However, the relative gas responses and gas selectivity depended closely on the catalyst loading. The loading of Pd enhanced the responses(R a /R g : R a : resistance in air, R g : resistance in gas) to CO and H 2 significantly, while it slightly deteriorated the response to C 2 H 5 OH. In contrast, a 3.1-fold enhancement was observed in the response to 100 ppm C 2 H 5 OH by loading of Ag onto SnO 2 nanowire networks. The role of Ag catalysts in the highly sensitive and selective detection of C 2 H 5 OH is discussed.