ZnO–TiO 2 nanocomposite: Characterization and moisture sensing studies

This paper reports morphological and relative humidity sensing behaviour of ZnO–TiO 2 nanocomposite powder pellets obtained through solid-state reaction route. Resistance of the pellets is observed to decrease with increase in relative humidity in the 10–90% range. Sensing element with 15 wt % of TiO 2 in ZnO shows best results with a sensitivity of 9 $\boldsymbol{\cdot}$ 08 M $\boldsymbol{\Omega} $ /%RH in 10–90% relative humidity range. This sensing element manifests crystallite size of 71 nm as measured from XRD and average grain size of 207 nm calculated from SEM micrograph. This sensing element manifests low hysteresis, less effect of ageing and good reproducibility. Response and recovery times of this sensing element are measured to be 84 s and 396 s, respectively.