Synthesis and characterization of TiO2 nanotubes for humidity sensing

The highly ordered TiO2 thin films are prepared by anodic oxidation and calcined at 300, 400, 500 and 600 degrees C, respectively. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) are employed to analyze the structure and the morphology of the TiO2 films. We design a novel sensor to investigate the humidity sensing behaviours of the samples. The samples calcined at 600 degrees C show high sensitivity with nearly two orders change in the resistance and short response and recovery time (< 190 s) during the relative humidity variation from 11 to 95%. (C) 2008 Elsevier B.V. All rights reserved.