Gas-Sensing Properties of Tin Oxide Nanohole Array

Abstract

The SnO ₂ nanohole arrays have been prepared by immersing an anodic alumina in ammonium hexafluorostannate solution at room temperature for a few hours. Pt, Au and Pd electrodes were sputtered on the tin oxide nanohole arrays. H2 gas sensing properties of SnO ₂ nanohole array sensors have been evaluated in dry air at 250-500 degree C. In the case of H2, every sensor showed quick response to H2 but fairly low sensitivity. Pt-SnO ₂ and Au-SnO ₂ sensors exhibited highest sensitivity at 500 degree C, and the sensitivity decreased as temperature decreased. On the other hand, Pd-SnO ₂ sensor exhibited resistance increase upon exposure to H ₂ at 300-400 degree C. This is probably due to resistance increase by the hydrogen solid solution in Pd electrode.