Fabrication of TiO2 sensor using rapid breakdown anodization method to measure pressure, humidity and sense gases at room temperature

Abstract

Rapid breakdown anodization (RBA) process was used to fabricate TiO₂ sensor to measure pressure and humidity and sense gases at room temperature. This chemical process transformed Ti to its oxide (TiO₂) as a powder with amorphous phase as X ray diffraction (XRD) technique confirmed.  This oxide consisted from semi spherical nanoparticles and titania nanotubes (TNTs) as Scanning electron microscope (SEM) technique showed.  TiO₂ powder was deposited on Ti substrates by using electrophoretic deposition (EPD) method.   Average pressure sensitivity was 0.34 MΩ/bar and hysteresis area was 1.4 MΩ .bar. Resistance of TiO₂ decreased exponentially with the increasing of relative humidity (RH%). The sensitivity% of TiO₂ for RH% was greater than 70% in the range of (50-95). TiO₂ was tested as a sensor for Ammonia, Ethanol and Methanol. Its sensitivity and selectivity towards Ammonia were the greatest but the shortest response and recovery times were recorded toward Methanol.