Humidity-sensitive properties of titania films prepared using the sol-gel process

Titanium isopropylalkoxide was used as a precursor to deposit TiO2 films on glass slides. The films were heated either to 300 C or to 500 C and the morphology of the film surface was observed using SEM. FTIR spectroscopy, XRD, XPS and electrochemical impedance spectroscopy at different relative humidities were carried out to study the possibility of using sol-gel processed titania films as detecting elements in humidity sensors. A good resistance versus relative humidity (rh) sensitivity was observed in the range from 50% to 85% rh. The response time of titania films was estimated at only a few seconds