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In this paper, a high-performance sensor based on tin oxide modified reduced graphene oxide (SnO 2 -rGO) has been prepared via a one-step hydrothermal process for the detection of sulfur hexafluoride (SF 6 ) decomposition components H 2 S and SOF 2 . The morphology and nanostructure of the product were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The gas sensing properties of SnO 2 -rGO nanocomposite were investigated by exposing to various target gases. The experimental results revealed that SnO 2 -rGO sensor exhibited better responses (34.31% and −3.13%) than those (5.97% and −1.45%) of pristine rGO sensor at the optimal temperature of 125 °C in the presentence 100 ppm H 2 S and 10 ppm SOF 2 , respectively. Meanwhile, SnO 2 -rGO sensor emerged as one of the promising candidate materials to select these two gases by yielding opposite response to H 2 S and SOF 2 . In addition, uniformity, repeatability, long-term stability of SnO 2 -rGO sensors were investigated to demonstrate the practicability, and the possible mechanism of SnO 2 -rGO nanocomposite for sensing H 2 S and SOF 2 was discussed. [ABSTRACT FROM AUTHOR]

The detection of the identities and concentrations of sulfur hexafluoride, SF 6 , decomposition products is important for evaluating the conditions of SF 6 -gas-insulated equipment. This study is a preliminary test of the use of cassiterite (110) for detecting SF 6 and SF 6 decomposition gases, including HF, H 2 S, SO 2 , SOF 2 , SO 2 F 2 , CF 4 , CO, and CO 2 . First-principles calculations were adopted to investigate the adsorption mechanism of SF 6 decomposition gases on a cassiterite (110) surface, using adsorption energy, geometrical structure, frontier molecular orbitals, electron density, density of states, potential energy, and work functions. We found that the adsorption of H 2 S made a noticeable change in the electronic properties of the (110) surface. The adsorption of SO 2 strongly influenced the charge distribution of the cassiterite (110) surface and made the greatest decrease in the work function of the nine gas molecules tested. Conversely, changes in the cassiterite's electronic properties induced by other gases, especially SF 6 , were slight. Therefore, cassiterite could be a promising candidate for highly selective and sensitive sensors to detect H 2 S and SO 2 in SF 6 decomposition gases. [ABSTRACT FROM AUTHOR]

• Adsorption properties of SF6 decomposition components on ceria surface were compared based on DFT calculations. • Adsorption of H 2 S, SO 2 and SOF 2 cause conspicuous charge redistribution on CeO 2 (110) surface. • CeO 2 (110) shows higher sensitivity to H 2 S, SO 2 and SOF 2 in comparison with SF 6. The detection of sulfur hexafluoride (SF 6) decomposition components is significant for monitoring the conditions of SF 6 -gas-insulated equipment. In present study, the adsorption of SF 6 and its decomposition components (H 2 S, SO 2 , SOF 2 , and SO 2 F 2) on ceria (110) was investigated by performing calculations based on density functional theory (DFT). Adsorption energy, adsorption configuration, charge transfer, density of states, potential energy and work function for molecular adsorption were adopted to evaluate the performance of ceria (110) on sensing SF 6 decomposition components. Among all the gas molecules, H 2 S, SO 2 and SOF 2 were chemically adsorbed on ceria surface with the adsorption energy following the order: SOF 2 > SO 2 > H 2 S, while SO 2 F 2 and SF 6 were physically adsorbed on the substrate. Besides, the amount of charge transfer and work function modification of H 2 S, SO 2 and SOF 2 molecule's adsorption were larger than those of SO 2 F 2 and SF 6. These calculation results demonstrated ceria (110) showed prominent sensitivity to H 2 S, SO 2 and SOF 2 while less activity to SF 6 , which means sensor based on ceria is promising for detecting H 2 S, SO 2 and SOF 2 in SF 6 gas background, and thus has the potential to online monitor the working condition of SF 6 -gas-insulated equipment. [ABSTRACT FROM AUTHOR]