PdO/SnO2 hollow nanospheres for carbon monoxide detection

SnO 2 hollow nanospheres (SnO 2 HNs) and different amount of PdO-doped SnO 2 HNs were successfully synthesized and applied to fabricate sensors for CO detection. The synthesized SnO 2 and PdO/SnO 2 materials have tetragonal and HN structure with a diameter of ∼180 nm, and the existence of Pd element is revealed by EDS and XPS. In addition, the sensors based on the pristine SnO 2 and Pd-loaded SnO 2 HNs were investigated for CO sensing properties. The experiment results indicated that materials of the best doping ratio is 1 mol%, because 1 mol% PdO/SnO 2 HN sensor had a lower optimized operating temperature (150 °C) and exhibited more excellent sensitivity than the other sensors for the detection of CO. Furthermore, the response value of 1 mol% PdO/SnO 2 HN sensor presented a linear relationship with CO concentration in the range 20–500 ppm CO at 150 °C. Meanwhile, 1 mol% PdO/SnO 2 HN sensor exhibited a remarkable selectivity to CO against volatile organic compounds. These results demonstrated that 1 mol% PdO/SnO 2 HNs are promising materials for application as a CO gas sensor when its working temperature is 150 °C. Comparison of PdO/SnO 2 hollow nanospheres with various amount of Pd loading for 200 ppm CO detection at different temperatures.