Synthesis and characterization of CdO-doped nanocrystalline ZnO:TiO2-based H2S gas sensor

This paper reports the preparation and gas-sensing characteristic of ZnO:TiO2-based hydrogen sulfide (H2S) gas sensor with different mol% of CdO by polymerized complex method. The structural and gas-sensing properties of ZnO:TiO2 materials have been characterized using X-ray diffraction and gas-sensing measurement. The electrical resistance response of the sensor based on the materials was investigated at different operating temperatures and different gas concentrations. The sensor with 10 mol% CdO-doped ZnO:TiO2 shows excellent electrical resistance response toward H2S gas. The cross sensitivity was also checked for reducing gases like CH4, CO and H2 gas. The selectivity and sensitivity of ZnO:TiO2-based H2S gas sensor were improved by the addition of 10 mol% of CdO at an operating temperature of 250 °C.