SnO2 Hollow Microspheres Used for Rapid and Sensitive Detection of Hydrogen Sulfide

Tin dioxide hollow microspheres(SnO2 HMS) were prepared using amino. phenol/formaldehyde resin spheres(APF) as templates. A novel thin. film type hydrogen sulfide(H2S) gas sensor was constructed by coating SnO2 HMS onto an alumina ceramic tube based Au electrode. The crystalline phase and microstructure of different nanomaterials were characterized by means of X-ray diffraction(XRD) and trans. mission electron microscopy(TEM), and the gas sensing properties of SnO2 HMS were studied in detail. The experimental results showed that SnO2 HMS had good sensing properties for H2S. At the optimum operating temperature of 200 degrees C, the response signal of the prepared sensor to 142. 6 mg/m(3) H2S was as high as 97. 13%, and the response time was very short, i.e. 22 s. The response linear range to H2S was from 0.2852 mg/m(3) to 142.6 mg/m(3), with a detection limit of 0.1549 mg/m(3), and the correlation coefficient was 0. 9931. Almost no effects on the sensor were observed from the environmental humidity and temperature. Also, the sensor possessed good reproducibility and selectivity. The sensor response signal reduced by 5. 4% after 10 months of continuous monitoring of H2S gas in a pig farm, indicating that the sensor has a long. term stable lifetime with valuable application for remote monitoring in practice.