A novel highly sensitive and selective H2S gas sensor at low temperatures based on SnO2 quantum dots-C60 nanohybrid: Experimental and theory study

Abstract

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 H2S, 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 H2S, 1% methane, and 1% propane gasses at low temperatures. The highest response (Rair/Rgas) of 66.0 and 5.4–70 ppm H2S 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 H2S gas. Also, DFT calculations were used for studying the interaction of these gases with SnO2-C60. DFT results showed that H2S has the strongest interaction and the highest effect on band-gap variation which is in a good agreement with experimental results.