Abstract:The perovskite-structure CdSnO 3 was obtained by calcinating CdSnO 3 ·3H 2 O precursor at 550 ℃, which was synthesized by hydrothermal process at 170 ℃ for 16 h. The phase and microstructure of the obtained CdSnO 3 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The CdSnO 3 powders exhibit uniformly cubic structure with side length of about 100 nm. The effects of working temperature and concentration of detected gas on the gas response were studied. The selectivity of chlorine gas against other gases and response-recovery time of the sensor were also investigated. The results reveal that the CdSnO 3 gas sensor has enhanced sensing properties to 1-10 ppm chlorine gas at room temperature; the value of gas response can reach 1338.9 to 5 ppm chlorine gas. Moreover, the sensor shows good selectivity and quick response behavior (23 s) to chlorine gas, indicating its application in detecting chlorine gas at room temperature in the future.