Thin film anodized titania nanotubes-based oxygen sensor

Abstract

Anodized titania, synthesized on oxidized silicon substrate, has been used as oxygen gas sensor. The as-anodized films resulted in a sensitivity of 5756% at 125°C, when exposed to 100% oxygen. The gas-sensing performance of anodized films has been evaluated with post-anodization treatment in de-ionized water and aqueous ammonia solution. The sensitivity increases to 8646% and 16599%, with post-treatment in aqueous ammonia solution and de-ionized water, respectively. This is attributed to increase surface area and activation during the post- anodization treatment. The repeatability of sensor performance has also been evaluated, and it is observed that the de-ionized water treated film is unstable for repeated sensing, possibly due to some structural modifications.