Hydrogen Gas Sensor Using Pt- and Pd-Added Anodic TiO2 Nanotube Films

TiO2 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 % NH4F and were applied as a resistance-type hydrogen gas sensor. A transmission electron microscopy analysis of the TiO2 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 TiO2 nanotube sensors showed a two-order decrease in resistance upon exposure to 1000 ppm H-2 at 290 degrees C and had little or no response to 1000 ppm CH4, 1000 ppm CO, and 1 ppm SO2. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3374643] All rights reserved.