Hydrogen Gas Sensor Using Pt- and Pd-Added Anodic TiO[sub 2] Nanotube Films

nanotube films were formed on pure Ti, Ti–Pt, and Ti–Pd thin films by anodization in a mixture of glycerol and water (1:1 volume ratio) containing 0.5 wt % and were applied as a resistance-type hydrogen gas sensor. A transmission electron microscopy analysis of the nanotube films revealed that the nanosized particles of Pt and Pd were dispersed in the wall of the nanotube. These dispersed Pt or Pd particles effectively improved the performance of the hydrogen gas sensor perhaps due to the acceleration of hydrogen chemisorption on the wall of the nanotube. Pt- and Pd-added nanotube sensors showed a two-order decrease in resistance upon exposure to 1000 ppm at and had little or no response to 1000 ppm , 1000 ppm CO, and 1 ppm .