Detection of Toluene Using CdS–TiO2 Thin Film Gas Sensor

Abstract

In recent years, significant interest has been shown in the design and development of sensing devices which can be used to identify toxic, combustible gases and organic vapors. The detection of air pollutants such as hydrocarbons, which often has to face in everyday life, is the necessity of mankind. In the present study, undoped and the CdS-doped titanium dioxide (CdS–TiO2) thin film has been fabricated on the glass substrate by the thermal evaporation method using High Hind Vacuum coating unit model number 12 A4D. The several samples of different thickness lie in rang (450 μm to 500 μm) were fabricated. The sensing properties of fabricated CdS-doped TiO2 thin film were examined for toluene gas at room temperature (300 K). The response and recovery time of the sensor were measured varying the concentration of toluene (0–5000 ppm) in air ambient and it is 22 for undoped TiO2 and 38 for CdS–TiO2 thin film. The response and recovery time of the sensors is the 70 s and 125 s for exposed toluene gas at room temperature. We observed that the fabricated CdS–TiO2 thin film is a suitable detector for detection of toluene gas at room temperature.