Humidity sensing properties of TiO2-Sb2O5 nanocomposite

The syntheses of TiO2-Sb2O5 (AT) composites were investigated by the conventional precipitation method and their use as humidity sensors. 2-50 wt. % of Sb2O5 was added to TiO2 and pellets were made under the pressure of 616 MPa a room temperature of 30°C. The pellets were annealed at various temperatures (200, 500, 700 and 800 °C) for 3 h and the humidity sensing properties of each pellet were studied. A saturated aqueous solution of potassium sulphate was used as the humidifier and a saturated solution of potassium hydroxide was used as the dehumidifier. Upon increasing relative humidity (RH) inside the test chamber, the resistance of each pellet decreased for the RH range from 10% to 95%. Samples of the sensor material, differing in the percentage of the additive, were subject to SEM and XRD analysis. The minimum grain size, estimated from SEM, was 30 nm and the minimum crystallite size from XRD data was 20 nm. The material was found to have suitable properties to be applied as a resistive humidity sensor operating over the entire humidity range.