Bilge Saruhan-Brings

P1.7.7 Hydrogen sensing properties of nanotubular TiO2, Al-and Cr-doped TiO2 sensor materials

There is an ongoing need to develop hydrogen (H2) gas sensors for industrial process control, combustion control and medical applications. Room temperature metal oxide hydrogen sensors are generally based on Schottky barrier modulation of Pd/TiO2 or Pt/TiO2 [1]. Currently available sensors are not sufficient to succeed high selectivity by detection of hydrogen gas above 500°C [2]. Titania (TiO2) is one of the most promising sensor materials for development of highly sensitive hydrogen sensors. It is low cost and non-toxic and has gained much attention owing to its high stability at elevated temperatures and in harsh environments. The nano-tubular structure formation on metallic titanium and some titanium alloys with electrolytic processes have improved the sensing and selectivity characteristics of titania-based hydrogen gas sensors [3]. Since the nanostructuring will provide larger surface area with high aspect ratio, nanotubular TiO2 achieved by electrolytic processing of metallic titanium opened up new horizons for increasing the sensing characteristics of titania-based gas sensors. Doping TiO2 with aluminum enhances selectivity towards hydrogen sensing [2]. In this present study, nano-tubular undoped TiO2, TiO2 doped with Al and Cr have been synthesized using both anodic oxidation process and sol-gel technique. These materials have utilized as sensor materials in hydrogen sensing measurements. The resistance changes of these nano-tubular sensors have measured under different concentrations of H2 in order to investigate the concentration dependence of sensor response.