A novel highly sensitive and selective H 2 S gas sensor at low temperatures based on SnO 2 quantum dots-C 60 nanohybrid: Experimental and theory study.

In this study, SnO2 quantum dots-fullerene (SnO2 QDs-C60 ) nanohybrid as novel sensing material was synthesized by a simple hydrothermal method. The structure and morphology of the synthesized sample were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The prepared hybrid was used as gas sensors for detection of different gasses including 70 ppm H2 S, 1% methane, and 1% propane at low temperatures of 100-200 °C. The results indicated that the SnO2 QDs-C60 nanohybrid has high response and high selectivity to 70 ppm H2 S, 1% methane, and 1% propane gasses at low temperatures. The highest response (Rair /Rgas ) of 66.0 and 5.4-70 ppm H2 S and 1% methane gasses at 150 °C and the response of 2.7-1% propane at 200 °C were observed for the prepared nanohybrid gas sensor. Moreover, the prepared sensor showed a good selectivity toward H2 S gas. Also, DFT calculations were used for studying the interaction of these gases with SnO2 -C60 . DFT results showed that H2 S has the strongest interaction and the highest effect on band-gap variation which is in a good agreement with experimental results.