Highly sensitive gas sensors based on hollow SnO2 spheres prepared by carbon sphere template method

Hollow SnO2 spheres were prepared in dimethylfomamide (DMF) by controlled hydrolysis of SnCl2 using newly made carbon microspheres as templates. The phase composition and morphology of the material particles were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The gas sensing properties of sensors based on the hollow SnO2 spheres were investigated. It was found that the sensor exhibited good performances, characterized by high response, good selectivity and very short response time to dilute (C2H5)3N operating at 150 °C, especially, the response to 1 ppb (C2H5)3N attained 7.1 at 150 °C. It was noteworthy that the response to 0.1 ppm C2H5OH of the sensor was 2.7 at 250 °C.